Dynamic Process Research Articles

Covalent Probes To Capture Legionella pneumophila Dup Effector Enzymes.

Upon infection of host cells, Legionella pneumophila releases a multitude of effector enzymes into the cell's cytoplasm that hijack a plethora of cellular activities, including the host ubiquitination pathways. Effectors belonging to the SidE-family are involved in noncanonical serine phosphoribosyl ubiquitination of host substrate proteins contributing to the formation of a Legionella-containing vacuole that is crucial in the onset of Legionnaires' disease. This dynamic process is reversed by effectors called Dups that hydrolyze the phosphodiester in the phosphoribosyl ubiquitinated protein. We installed reactive warheads on chemically prepared ribosylated ubiquitin to generate a set of probes targeting these Legionella enzymes. In vitro tests on recombinant DupA revealed that a vinyl sulfonate warhead was most efficient in covalent complex formation. Mutagenesis and X-ray crystallography approaches were used to identify the site of covalent cross-linking to be an allosteric cysteine residue. The subsequent application of this probe highlights the potential to selectively enrich the Dup enzymes from Legionella-infected cell lysates.

Simulation-Guided Preparation of Copper Chalcogenide Nanoparticle-Based Transparent Photothermal Coating with Enhanced Deicing Performance.

In this investigation, transparent photothermal coatings utilizing plasmonic copper chalcogenide (Cu2-xS) nanoparticles were designed and fabricated for the deicing of glass surfaces. Cu2-xS nanoparticles, chosen for their high near-infrared (NIR) absorption and efficient photothermal conversion, were analyzed via finite difference time domain (FDTD) simulations to optimize nanoparticle morphology, thus avoiding costly trial-and-error synthesis. FDTD simulations determined that Cu2-xS nanorods (Cu-NRs) with an optimal aspect ratio of 2.2 had superior NIR absorption. Guided by FDTD simulations, the composite coating composed of Cu-NRs in clear acrylic resin paint was brush-coated to glass, achieving 62.4% visual transmittance and over 95% NIR absorbance. Photothermal conversion tests exhibited a significant temperature increase, with the coating reaching 65 °C under NIR irradiation within 6 min. The dynamic deicing process of ice beads on the coating at -20 °C completed within 220s, in contrast to the frozen state on glass coated with clear acrylic resin paint. Furthermore, heat transfer simulations in COMSOL illustrated melting initiation at the ice-coating interface and subsequent progression through the ice layer. This simulation-driven synthesis method and photothermal testing offer a design framework for the fabrication of photothermal deicing coatings with applications for automobiles, buildings, and aircraft in cold environments.

Lamellipodia-Mediated Osteoblast Haptotaxis Guided by Fibronectin Ligand Concentrations on a Multiplex Chip.

Skull morphogenesis is a complex, dynamic process involving two different germ layers and progressing to the coordinated, directional growth of individual bones. The mechanisms underlying directional growth toward the apex are not completely understood. Here, a microfluidic chip-based approach is utilized to test whether calvarial osteoblast progenitors undergo haptotaxis on a gradient of Fibronectin1 (FN1) via lamellipodia. Mimicking the embryonic cranial mesenchyme's FN1 pattern, FN1 gradients is established in the chip using computer modeling and fluorescent labeling. Primary mouse calvarial osteoblast progenitors are plated in the chip along an array of segmented gradients of adsorbed FN1. The study performs single-cell tracking and measures protrusive activity. Haptotaxis is observed at an intermediate FN1 concentration, with an average directional migration index (yFMI) of 0.07, showing a significant increase compared to the control average yFMI of -0.01. A significant increase in protrusive activity is observed during haptotaxis. Haptotaxis is an Arp2/3-dependent, lamellipodia-mediated process. Calvarial osteoblast progenitors treated with the Arp2/3 (Actin Related Protein 2/3 complex) inhibitor CK666 show significantly diminished haptotaxis, with an average yFMI of 0.01. Together, these results demonstrate haptotaxis on an FN1 gradient as a new mechanism in the apical expansion of calvarial osteoblast progenitors during development and shed light on the etiology of calvarial defects.

Kierkegaard’s reconceptualisation of divine immutability

In Søren Kierkegaard’s works, the relationship between the immutability of God and the concepts of time and motion emerges as a central theme. This paper examines how Kierkegaard reconciles the idea of an immutable God with the dynamic process of ‘coming into existence’. Through an exploration of Kierkegaard’s philosophical roots, this study elucidates his understanding of motion and change, delves into his ontological and metaphysical notions of time, and particularly focusses on the ‘moment’ as a synthesis that bridges the eternal God with the individual’s dynamical existence. Kierkegaard’s theory of divine immutability represents a genuine departure from traditional metaphysical thought; comparing his ideas with those of other philosophers would highlight the uniqueness of Kierkegaard’s approach.Contribution: This article aims to analyse the philosophical foundation of God’s immutability through a detailed interpretation of Kierkegaard’s writings, providing a new approach to understanding the movement and immutability of God.

Multifocal microscopy for functional imaging of neural systems.

Rapid acquisition of large imaging volumes with microscopic resolution is an essential unmet need in biological research, especially for monitoring rapid dynamical processes such as fast activity in distributed neural systems. We present a multifocal strategy for fast, volumetric, diffraction-limited resolution imaging over relatively large and scalable fields of view (FOV) using single-camera exposures. Our multifocal microscopy approach leverages diffraction to image multiple focal depths simultaneously. It is based on a custom-designed diffractive optical element suited to low magnification and large FOV applications and customized prisms for chromatic correction, allowing for wide bandwidth fluorescence imaging. We integrate this system within a conventional microscope and demonstrate that our design can be used flexibly with a variety of magnification/numerical aperture (NA) objectives. We first experimentally and numerically validate this system for large FOV microscope imaging (three orders-of-magnitude larger volumes than previously shown) at resolutions compatible with cellular imaging. We then demonstrate the utility of this approach by visualizing high resolution three-dimensional (3D) distributed neural network at volume rates up to 100Hz. These demonstrations use genetically encoded indicators to measure functional neural imaging both in vitro and in vivo. Finally, we explore its potential in other important applications, including blood flow visualization and real-time, microscopic, volumetric rendering. Our study demonstrates the advantage of diffraction-based multifocal imaging techniques for 3D imaging of mm-scale objects from a single-camera exposure, with important applications in functional neural imaging and other areas benefiting from volumetric imaging.

Understanding the High-Temperature Deformation Behaviors in Additively Manufactured Al6061+TiC Composites via In Situ Neutron Diffraction

Aluminum matrix composites (AMCs) are designed to enhance the performance of conventional aluminum alloys for engineering applications at both room and elevated temperatures. However, the dynamic phase-specific deformation behavior and load-sharing mechanisms of AMCs at elevated temperatures have not been extensively studied and remain unclear. Here, in situ neutron diffraction experiments are employed to reveal the phase-specific structure evolution of additively manufactured Al6061+TiC composites under compressive loading at 250 °C. It is found that the addition of a small amount of nano-size TiC significantly alters the deformation behavior and increases the strength at 250 °C in comparison to the as-printed Al6061. Unlike the two-stage behavior observed in Al6061, the Al6061+TiC composites exhibit three stages during compression triggered by changes in the interphase stress states. Further analysis of Bragg peak intensity and broadening reveals that the presence of TiC alters the dislocation activity during deformation at 250 °C by influencing dislocation slip planes and promoting dislocation accumulation. These findings provide direct experimental observations of the phase-specific dynamic process in AMCs under deformation at an elevated temperature. The revealed mechanisms provide insights for the future design and optimization of high-performance AMCs.

Dynamic Imaging of Electrochemically Induced Transformations in Layered Tin Chalcogenide Catalysts.

Understanding the dynamic transformation processes of electrocatalysts during electrochemical reactions is crucial for the development of advanced materials for energy conversion and storage, yet it remains a challenge. Herein, we report the real-time monitoring of the dynamic transformation of a series of layered Sn chalcogenides during electrochemical reduction using a plasmonic imaging method. Taking SnSe2 as an example, we observed a strong firework-like emission diffusing outward from SnSe2 to the surrounding solution under a negative potential. The diffusion coefficient of the observed species is indicative of Sn nanoclusters rather than smaller ions. This study also extends to SnSe and SnS2 nanosheets, demonstrating the general applicability of plasmonic imaging for probing the stability and transformation mechanism of heterogeneous catalysts in electrocatalytic reactions. These insights provide a foundational understanding for designing more stable and efficient electrocatalysts for industrial applications.

Unveiling the dynamic processes of dietary advanced glycation end-products (dAGEs) in absorption, accumulation, and gut microbiota metabolism.

This study delves into the dynamics of dietary advanced glycation end-products (dAGEs) on host health and gut microbiota. Using 13C-labeled carboxymethyllysine (CML) bound casein, we identify bound AGEs as the primary entry route, in contrast to free AGEs dominating urinary excretion. Specifically, our results show that the kidneys accumulate 1.5 times more dAGEs than the liver. A high AGE (HA) diet prompts rapid gut microbiota changes, with an initial stress-induced mutation phase, evidenced by a 20% increase in Bacteroides and Parabacteroides within the first week, followed by stabilization. These bacteria emerge as potential dAGE-utilizing bacteria, influencing the microbiota composition. Concurrent metabolic shifts affect lipid and carbohydrate pathways, with lipid metabolism alterations persisting over time, impacting host metabolic homeostasis. This study illuminates the intricate interplay between dietary AGEs, gut microbiota, and host health, offering insights into the health consequences of short- and long-term HA dietary patterns.

Da_Tracker: Automated workflow for high throughput single cell and single phagosome tracking in infected cells.

Time-lapse microscopy has emerged as a crucial tool in cell biology, facilitating a deeper understanding of dynamic cellular processes. While existing tracking tools have proven effective in detecting and monitoring objects over time, the quantification of signals within these tracked objects often faces implementation constraints. In the context of infectious diseases, the quantification of signals at localized compartments within the cell and around intracellular pathogens can provide even deeper insight into the interactions between the pathogen and host cell organelles. Existing quantitative analysis at a single-phagosome level remains limited and dependent on manual tracking methods. We developed a near-fully automated workflow that performs with limited bias, high-throughput cell segmentation and quantitative tracking of both single cell and single bacterium/phagosome within multi-channel, z-stack, time-lapse confocal microscopy videos. We took advantage of the PyImageJ library to bring Fiji functionality into a Python environment and combined deep-learning-based segmentation from Cellpose with tracking algorithms from Trackmate. The 'da_tracker' workflow provides a versatile toolkit of functions for measuring relevant signal parameters at the single-cell level (such as velocity or bacterial burden) and at the single-phagosome level (i.e. assessment of phagosome maturation over time). Its capabilities in both single-cell and single-phagosome quantification, its flexibility and open-source nature should assist studies that aim to decipher for example the pathogenicity of bacteria and the mechanism of virulence factors that could pave the way for the development of innovative therapeutic approaches.

Research on the Green Transition Path of Airport Development under the Mechanism of Tripartite Evolutionary Game Model

Since existing studies primarily explore green development measures from the static perspective of a single airport stakeholder, this paper constructs an evolutionary game model to analyze the strategic choices of three key stakeholders: airport authorities, third-party organizations, and government departments, based on evolutionary game theory. By solving the stable strategy of the tripartite evolution using the Jacobian matrix, the green transition of airport development can be divided into three stages: “initiation”, “development”, and “maturity”, allowing for the exploration of key factors influencing the green transition of airport development. A simulation analysis is conducted based on real Guangzhou Baiyun International Airport data. The results indicate that the tripartite evolutionary game strategy is stable at E4(0,0,1) and the green transition of Baiyun Airport remains in the development stage. By improving the reward and punishment mechanisms of government departments, the evolutionary game strategy can be stabilized at E8(1,1,1), promoting the green transition of airport development toward the mature stage. By adjusting the game parameters, the dynamic process of green transition in airports at different levels of development and under varying regulatory environments can be effectively captured, supporting the precise formulation of corresponding policies.

Integrating calibrated PTFs and modified OpenKarHydro framework to map the responses of ecohydrological processes to climate change across the Loess Plateau

Climate change is exacerbating the risk of soil water stress, soil erosion and ecological degradation in the Loess Plateau (CLP). However, the spatiotemporal dynamics of ecohydrological processes, including soil water balance (SWB), soil erosion (SE) and vegetation net primary productivity (NPP), in response to climate change remain isolated and ambiguous. Additionally, existing studies often rely on limited measured data from specific watersheds with particular land use/cover types to establish the pedotransfer functions (PTFs) for single soil hydraulic parameter (SHP). There is a notable lack of comprehensive studies that explore PTFs encompassing all SHPs applicable to the entire CLP, predict the spatiotemporal response of ecohydrological processes to climate change, and identify future risk periods and regions for SWB, SE, and NPP. To address these gaps, we first screened the PTFs applicable for the whole CLP, and then projected the spatiotemporal dynamics of ecohydrological processes from 2020 to 2030 under CMIP6 scenarios by integrating the PTFs with the OpenKarHydro, RUSLE, and CASA model, and finally classified the soil water content, SE and NPP to identify their risk periods and regions. The results showed that the PTFs achieved satisfactory accuracy, with RMSEs for Ks, θs, θr, α, n, θfc and θw being 2.682, 0.109, 0.016, 0.111, 0.897, 0.060 and 0.058, BIASs of 1.365, 0.182, 0.012, 0.031, 0.214, 0.057 and 0.048, R2s of 0.445, 0.500, 0.430, 0.400, 0.694, 0.453 and 0.453, and NSEs of 0.645, 0.737, 0.874, 0.349, 0.567, 0.756 and 0.458, respectively. SE decreased significantly from 2020 to 2030, with an average annual rate of −6.18 %. Soil water storage decreased significantly between 2020 and 2030, and declining from southeast to northwest. The proportion of area in the wet zone decreased by 4 %, while the proportion of area in the dry zone increased by 11.9 % from 2020 to 2030. The average NPP in 2020–2030 is 320.07 gC·m−2·a−1, with the largest in summer and smallest in winter, and decreasing from southeast to northwest. The NPP increased significantly in 2020–2030, with average annual value and rate of 19.61 gC·m−2·a−1 and 70.84 %, respectively. The NPP increased significantly in spring, summer and autumn, but remained stable in winter. This investigation bridges the gap between existing soil properties, missing SHPs, the strong regional applicability of PTFs, and isolated ecohydrological processes. It is promises to provide valuable insights into the response to climate change in the CLP and another water-limited regions.

Weaving the real and the virtual: young urban Indonesians’ lived experiences of making psychological homes

ABSTRACT Home-making processes have been an important subject of investigation for decades. This research furthers the scholarship in this area by exploring how young urban Indonesians develop psychological homes to create habitable spaces for themselves, with reference to their various relational networks, activities, objects, and pets. We draw on fieldwork conducted over a 16-week period with 45 young people in Surabaya and subsequently extended through diary analysis. To analyze and interpret the empirical materials generated, we drew insights from assemblage theory which revealed that the lived experiences of youth in developing psychological homes for themselves are fluid and dynamic processes, involving both human and physical elements. Our exploration began with the key elements that participants used to develop psychological homes. We then also explored their practices in weaving together these key elements to navigate everyday tensions within their broader relational networks. This article demonstrates the utility of assemblage thinking in unpacking the everyday practices of homemaking among youth.

Synthesis, characterization and application of quinoxaline-based organic dyes as anodic sensitizers in photoelectrochemical cells

Three new D-A-π-A organic dyes (1a-c) containing a 2,3-diphenylquinoxaline core as the main chromophore were designed to act as sensitizers for the TiO2-based photoanode of dye-sensitized photoelectrochemical cells (DS-PEC) for water splitting. The dyes structures featured a cyanoacrylic acid group as the terminal acceptor/anchoring moiety and three different donor groups of moderate strength, namely mono- and dialkoxy-substituted benzenes, which were introduced to modulate the energies of the respective HOMO levels and enable the electron transfer from a Ru-based molecular water oxidation catalyst (WOC). Dyes 1a-c were synthesized following a C–H activation strategy and fully characterized. In addition, the previously known catalyst Ru(bda)(PyP)2 (bda = 2,2′-bipyridine-6,6′-dicarboxylate; PyP = pyridin-4-methyl phosphonic acid) was also prepared by modification of a reported procedure. The dynamics of charge transfer processes involving the dyes adsorbed on nanocrystalline TiO2 films were investigated by means of transient absorption spectroscopy. Photo-electrochemical experiments carried out on photoanodes functionalized with 1a-c and Ru(bda)(PyP)2 in 0.1 M aq. Na2SO4 electrolyte showed the production of photocurrents up to ca. 0.15 mA cm−2 at + 0.5 V vs. NHE, and highlighted how modifications of the TiO2 staining procedure can lead to significant differences in cell performances.

REVIEW AND COMPARATIVE STUDY OF HYDROLOGICAL MODELS FOR RAINFALL-RUNOFF MODELLING

Water is considered as an important resources for human existence on the earth. In order to simulate or optimized hydrological data for various water resources management, several hydrological models are very useful to attain this aim for water resources management and as a decision support tools. A rainfall-runoff model is a quantitative prototype explaining the rainfall-runoff interactions at basin scale. The hydrological models have peculiarities in terms of capabilities for various water resources management. This paper tends to reviewed over fifty (50) papers that are peculiar to hydrological models as applicable to rainfall-runoff modeling. It involved evaluating and comparing different hydrological models used in simulating rainfall process converting into surface runoff for water use efficiency. Several runoff models such as Hydrologic Engineering Center - Hydrologic Modeling System (HEC-HMS), Soil and Water Assessment Tool (SWAT), Precipitation-Runoff Modeling System (PRMS), Variable Infiltration Capacity model (VIC), LISt-based Erosion Model (LISEM), MIKE Surface Water - Groundwater Hydrology (MIKE SHE) and Runoff Prophet were critically assessed. Rainfall-runoff models are globally utilized for different applications to enhance water use efficiency across different sectors. However, types of hydrological models by examining various hydrological models, model accuracy by evaluating the accuracy and reliability of each model in predicting runoff from rainfall data, scope of applications by determining the adequacy of the models for numerous geographical regions and climatic circumstances, complexity and usability by assessing the complexity of the models, their data requirements, ease of use and computational efficiency, also the models advantages and limitations in capturing the dynamics of the rainfall-runoff process were critically assessed. This was to aid modeling objectives. It was inferred that HEC-HMS is widely applied for modelling precipitation-runoff processes in watersheds of various sizes, aiding in flood forecasting, reservoir operation, and water management for agricultural and urban water use efficiency. SWAT is used for assessing the impact of land management practices (e.g., crop rotation, irrigation, land use changes) on water resources, including runoff generation and water quality, thus optimizing water use efficiency in agriculture. PRMS is applied to model the transport of water via complex hydrological systems, aiding in watershed management and water use efficiency assessments. In conclusion, this comparative review seeks to guide water scientists, the users of hydrological models and hydrological engineers in selecting the most suitable models for their specific modelling needs for sustainable water resources management.

Behaviors of hydrate cap formation via CO2-H2O collaborative injection:Applying to secure marine carbon storage

Leakage prevention of carbon dioxide (CO2) determines the safety of carbon marine geological storage. Hydrate caps have been proven to be one of the most effective structures for preventing CO2 leakage, which has attracted worldwide attention. However, the structure and formation behavior of hydrate caps during CO2 storage process are still unclear. In this study, a strategy of CO2-H2O co-injection was proposed to simulate the actual flow process and accelerate the hydrate cap formation rate. A series of CO2-H2O flow rates (0.25–10 mL/min) were employed. The results show that there will be four stages for the dynamic formation process of hydrate cap: fluid migration and diffusion, local hydrate formation, local area plugging, and hydrate cap formation. What's more, the water-gas flow ratio is inversely proportional to hydrate cap formation rate and positively proportional to the carbon storage efficiency. Meanwhile, the huge sealed capacity of hydrate cap was also proved in this work. The sequestration pressure of CO2 under hydrate cap exceeds 12 MPa, and the maximum carbon storage efficiency increases from 53.12% to 93.30%. Moreover, the macrostructure of hydrate cap consists of two layers with a certain hydrate saturation: the zero-permeability layer and the low-permeability layer. The zero-permeability layer determined the sealed capacity of hydrate cap. These findings may provide a theoretical foundation for the prevention of CO2 leakage in actual project of carbon marine geological storage.

Dynamic layer-specific processing in the prefrontal cortex during working memory

The dorsolateral prefrontal cortex (dlPFC) is reliably engaged in working memory (WM) and comprises different cytoarchitectonic layers, yet their functional role in human WM is unclear. Here, participants completed a delayed-match-to-sample task while undergoing functional magnetic resonance imaging (fMRI) at ultra-high resolution. We examine layer-specific activity to manipulations in WM load and motor response. Superficial layers exhibit a preferential response to WM load during the delay and retrieval periods of a WM task, indicating a lamina-specific activation of the frontoparietal network. Multivariate patterns encoding WM load in the superficial layer dynamically change across the three periods of the task. Last, superficial and deep layers are non-differentially involved in the motor response, challenging earlier findings of a preferential deep layer activation. Taken together, our results provide new insights into the functional laminar circuitry of the dlPFC during WM and support a dynamic account of dlPFC coding.

The influence of erosion on the dynamic process of landslide in Xinmo Village, Maoxian

A large-scale, high-speed, long-runout landslide occurred in Xinmo Village, Maoxian, Sichuan Province, China, on June 24, 2017. It was characterized by fast sliding speed, rapid volume growth, and large impact area. The dynamic process of such landslides and the influence of erosion on the dynamic process are studied by field investigation, numerical inversion and simulation. The results showed that entrainment erosion was a major factor of landslide volumetric change and a salient feature of the landslide process. An exponential equation relating the erosion rate and the deposition volume was established. Moreover, the study found that a slight change of the erosion rate (1e-4) also had a significant impact on the lateral spreading, longitudinal runout, and vertical erosion. As the erosion rate increased, the lateral spreading, longitudinal runout, and vertical erosion of this type of landslide became more obvious. By using the coefficient of variation method, it was obtained that the erosion rate had a greater influence on the vertical erosion than on the lateral spreading and longitudinal runout. In the study of the velocity of the rock avalanche under different erosion conditions, it was found that the erosion amount and the landslide velocity were not strictly linearly related. This study has important significance for understanding the dynamic process and erosion effect of rock avalanche, and provides useful references and insights for future research in related fields.

Modeling engagement with a digital behavior change intervention (HeartSteps II): An exploratory system identification approach

ObjectiveDigital behavior change interventions (DBCIs) are feasibly effective tools for addressing physical activity. However, in-depth understanding of participants’ long-term engagement with DBCIs remains sparse. Since the effectiveness of DBCIs to impact behavior change depends, in part, upon participant engagement, there is a need to better understand engagement as a dynamic process in response to an individual’s ever-changing biological, psychological, social, and environmental context. MethodsThe year-long micro-randomized trial (MRT) HeartSteps II provides an unprecedented opportunity to investigate DBCI engagement among ethnically diverse participants. We combined data streams from wearable sensors (Fitbit Versa, i.e., walking behavior), the HeartSteps II app (i.e. page views), and ecological momentary assessments (EMAs, i.e. perceived intrinsic and extrinsic motivation) to build the idiographic models. A system identification approach and a fluid analogy model were used to conduct autoregressive with exogenous input (ARX) analyses that tested hypothesized relationships between these variables inspired by Self-Determination Theory (SDT) with DBCI engagement through time. ResultsData from 11 HeartSteps II participants was used to test aspects of the hypothesized SDT dynamic model. The average age was 46.33 (SD=7.4) years, and the average steps per day at baseline was 5,507 steps (SD=6,239). The hypothesized 5-input SDT-inspired ARX model for app engagement resulted in a 31.75 % weighted RMSEA (31.50 % on validation and 31.91 % on estimation), indicating that the model predicted app page views almost 32 % better relative to the mean of the data. Among Hispanic/Latino participants, the average overall model fit across inventories of the SDT fluid analogy was 34.22 % (SD=10.53) compared to 22.39 % (SD=6.36) among non-Hispanic/Latino Whites, a difference of 11.83 %. Across individuals, the number of daily notification prompts received by the participant was positively associated with increased app page views. The weekend/weekday indicator and perceived daily busyness were also found to be key predictors of the number of daily application page views. ConclusionsThis novel approach has significant implications for both personalized and adaptive DBCIs by identifying factors that foster or undermine engagement in an individual’s respective context. Once identified, these factors can be tailored to promote engagement and support sustained behavior change over time.

The influence of follower reactions on political leaders’ environmental policy communication: toward a social-mediated dynamic influence framework

ABSTRACT This study proposes that social-mediated leadership communication is a dynamic influence process, involving visible leader communications, follower emotional responses, and subsequent leader actions. These interactions form a feedback loop, where follower reactions influence leaders' strategic communication. We tested this framework by analyzing U.S. political leaders' engagement with the Green New Deal during the 2020 Presidential campaign. Using Facebook posts from congressional politicians and data on follower reactions, we applied longitudinal network models, natural language processing, and multilevel event history models to examine factors behind leaders' decisions to co-share content and discuss specific policy topics. Our findings support the dynamic influence framework, showing that follower reactions, especially those indicating support and boosting message virality, are most likely to prompt shifts in leaders’ communication strategies.

Design, development and multi-scenario application of portable multifunctional test master based on μM-PMU: The case study of Lingang new City Grid, Shanghai

With the large-scale access of new energy generation and electric vehicle charging piles to the grids, power generation and loads are characterized by random fluctuations and intermittency, which affect the stable operation of the distribution network. μM-PMU is capable of realizing the dynamic process monitoring of the grids. In order to solve the function and performance testing problems of multiple application scenarios of μM-PMU, this thesis develops a portable master station based on synchronous phasor measurement system to realize zero drift, voltage amplitude measurement accuracy, voltage phase angle accuracy, current amplitude measurement accuracy, current phase angle measurement accuracy, frequency measurement accuracy, voltage amplitude change with frequency accuracy, and voltage phase angle change with frequency accuracy, Accuracy of current amplitude with frequency change, accuracy of current phase angle with frequency change, active power accuracy, reactive power accuracy, amplitude step response, phase angle step response, frequency step response, a total of 15 test items. It can automatically calculate test results and generate test reports according to different equipment models, reducing the mistakes and calculation errors that may be caused by manually recording test data and improving the accuracy of test results and calculation precision.