Central Mode Research Articles

Parametric instability in the pure-quartic nonlinear Schrödinger equation

We study the nonlinear stage of modulation instability (MI) in the non-intergrable pure-quartic nonlinear Schrödinger equation where the fourth-order dispersion is modulated periodically. Using the three-mode truncation, we reveal the complex recurrence of parametric resonance (PR) breathers, where each recurrence is associated with two oscillation periods (PR period and internal oscillation period). The nonlinear stage of parametric instability admits the maximum energy exchange between the spectrum sidebands and central mode occurring outside the MI gain band.

Sea Ice‐Driven Variability in the Pacific Subantarctic Mode Water Formation Regions

AbstractSubantarctic Mode Water (SAMW) forms north of the Subantarctic Front, in regions of deep winter mixed layers, and is important to the absorption and storage of anthropogenic CO2 and heat. Two SAMW pools exist in the Pacific, a lighter Central mode (CPSAMW), and a denser Southeast mode (SEPSAMW). Both have experienced significant interannual variability in thickness and properties in recent years. We compute mixed layer temperature and salinity budgets for the two SAMW formation regions, to determine the relative contribution of processes driving variability in the properties of mixed layers that subduct to form SAMW. The dominant drivers of temperature and salinity variability are shown to be surface fluxes, horizontal advection, and entrainment of deeper water. Salt advection into each SAMW formation region is found to be strongly correlated with changes in sea ice area in the northern Ross Sea, with lags of up to 2 years. Further correlation is found between meridional salt advection in the southeast Pacific formation regions, and sea ice area in the northern Amundsen/Bellingshausen seas, suggesting that freshwater derived from sea ice melt reaches the SEPSAMW formation region within 6 months. In 2016, strong advective freshening of the SEPSAMW formation region, linked to increased winter sea ice in the Amundsen/Bellingshausen seas, led to anomalously fresh mixed layers. However, a regime change in Antarctic sea ice in 2016 resulted in a subsequent lack of the usual advective freshening in the SEPSAMW formation region, driving increased salinity of the mixed layer the following year.

Random Mutational Analysis Targeting Residue K155 within the Transmembrane β-Hairpin of the Mosquitocidal Mpp46Ab Toxin.

Mpp46Ab is a mosquito-larvicidal pore-forming toxin derived from Bacillus thuringiensis TK-E6. Pore formation is believed to be a central mode of Mpp46Ab action, and the cation selectivity of the channel pores, in particular, is closely related to its mosquito-larvicidal activity. In the present study, we constructed a mutant library in which residue K155 within the transmembrane β-hairpin was randomly replaced with other amino acid residues. Upon mutagenesis and following primary screening using Culex pipiens mosquito larvae, we obtained 15 mutants in addition to the wild-type toxin. Bioassays using purified proteins revealed that two mutants, K155E and K155I, exhibited toxicity significantly higher than that of the wild-type toxin. Although increased cation selectivity was previously reported for K155E channel pores, we demonstrated in the present study that the cation selectivity of K155I channel pores was also significantly increased. Considering the characteristics of the amino acids, the charge of residue 155 may not directly affect the cation selectivity of Mpp46Ab channel pores. Replacement of K155 with glutamic acid or isoleucine may induce a similar conformational change in the region associated with the ion selectivity of the Mpp46Ab channel pores. Mutagenesis targeting the transmembrane β-hairpin may be an effective strategy for enhancing the ion permeability of the channel pores and the resulting mosquito-larvicidal activity of Mpp46Ab.

Gene mutations as predictors of central lymph mode metastasis in cN0 PTC: A meta-analysis.

Gene mutations could predict the tumor progression and prognosis, which are usto predict CLNM in patients with cN0 PTC, however, these results are not consistent. This meta-analysis tried to identify gene mutations which could predict CLNM in patients with cN0 PTC. A systematic search was performed for identifying relevant literature published prior to July 2023 in three search engines: PubMed, EMBASE and Web of Science. Studies that investigated the gene mutations for CLNM in patients with cN0 PTC were included in our meta-analysis. Sixteen studies, including 6095 cN0 PTC with BRAF mutations were include in our meta-analysis. The prevalence of CLNM in cN0 PTC ranged from 13.7% to 50.6%. The pooled analysis demonstrated that BRAFV600E mutation is significantly associated with CLNM (OR = 2.01, 95% CI: 1.55-2.60, p < 0.001) in PTC and PTMC (OR = 1.70, 95% CI: 0.51-1.81, p < 0.001). Whereas, cN0 PTC with TERT (OR = 1.94, 95% CI: 0.51-7.36, p = 0.33) and KRAS (OR = 0.57, 95% CI: 0.51-1.81, p = 0.34) mutations might not contribute to predictCLNM. Our analysis identified that BRAF mutation was a predictive factor for cN0 PTC, as well as for cN0 PTMC, which could be useful for clinician to accurately choose prophylactic CLND and better manage cN0 PTC.

Effects of the Last Deglaciation climate warming on hydrate dissociation in the northern South China Sea

Sea level and bottom water temperature variations caused by the Last Deglaciation climate warming impacted the stability of marine hydrates. In order to examine their influence on hydrate dissociation in the northern South China Sea (SCS), we conducted simulations to track the evolution of hydrate saturation and hydrate occurrence zone since the Last Deglaciation in the Dongsha Area, Shenhu Area, Xisha Area and Qiongdongnan Area. The amount of methane generated and subsequently released into seawater and atmosphere was also evaluated within the four areas. The simulation revealed the following results: (1) Hydrate dissociation induced by variations in sea level and bottom water temperature was observed in the Dongsha Area, Xisha Area and Qiongdongnan Area, but not in the Shenhu Area. (2) The water depth at which hydrate dissociation occurred ranged between 480 and 720 m, encompassing a hydrate dissociation area of approximately 1.54 × 1010 m2. This accounted for 6.68% of the northern South China Sea Area. (3) Since the Last Deglaciation, an estimation of 3.08 × 108–1.48 × 1010 m3 hydrates have dissociated, resulting in the release of 5.05 × 1010–2.43 × 1012 m3 methane. The generated methane migrated through the overlying sediments by means of central migration mode. 9.9 × 109–4.76 × 1011 m3 methane entered into the seawater, which will result in the formation of a weak acid affecting the marine environment. Meanwhile, 2.02 × 108–9.72 × 109 m3 methane entered into the atmosphere, which leads to an increase in greenhouse gas concentrations.

A-267 Evaluation of the Quidel Sofia 2 Rapid Lyme Test in a Modified Two-tier Testing Protocol

Abstract Background Several Modified two-tier testing algorithms (MTTT) for Lyme disease involving sequential enzyme immunoassays (EIA) have been approved by the FDA as an alternative to conventional two-tiered testing using EIA followed by immunoblot. The MTTT algorithms are reported to be more sensitive than conventional two-tiered algorithm’s especially in early Lyme disease. The Quidel Sofia 2 Lyme assay utilizes lateral flow with fluorescence detection (FIA) providing a rapid on-demand instrument-read alternative to central laboratory batch mode testing We compared the Quidel assay as a first-tier test in an MTTT algorithm to the Zeus Scientific VlsE1/pepC10 IgG/IgM enzyme immunoassay (EIA) followed by the Zeus monovalent IgM and IgG EIA as the confirmatory test. Methods Serum specimens (n = 179) were obtained from consecutive samples sent to our clinical laboratory for Lyme serology testing. For the first-tier the samples were tested using the Zeus EIA VlsE1/pepC10 lgG/IgM test and the Quidel Sofia 2 Lyme FIA assay. Positive or equivocal first-tier tests were then tested using the Zeus monovalent IgM and IgG EIA as the confirmatory test. Results The positive percent agreement was 100%, the negative percent agreement 97.9 % with an overall agreement of 98.3%. The Kappa statistic was 0.945 (95% confidence interval 0.883–1.000 indicating “almost perfect” agreement). Conclusion The Quidel Sofia Lyme test performs well when compared to the Zeus test in a two-tiered testing MTTT algorithm. Obtaining samples to evaluate Lyme serologic tests can be challenging. Our data should prove useful for facilities considering the use of the Quidel assay.

Comprehensive Evaluation of Different Heating Modes in Northeast China

Given the freezing temperatures and extended winters, heating is essential for residents living in Northeast China. When selecting the optimum heating mode for the region, various factors are taken into consideration, such as the impact on the environment, financial cost and energy consumption. However, it is uncertain which heating mode can fulfill all conditions and requirements. In this study, seven heating modes were selected from the national and northeastern heating strategies. A comprehensive index system based on the life cycle theory was developed from the perspectives of energy, the environment, the economy, technology and society. Additionally, a comprehensive evaluation of the seven heating modes was performed using the analytical hierarchy process (AHP) and gray relation analysis. The results of this research showed that, from a complete standpoint, the ground-source heat pump heating mode (HMg) had the best comprehensive benefit, with a correlation of 0.8173, followed by the coal-fired cogeneration heating mode (HMcc), which had the highest correlation degree among the centralized heating modes at 0.6111. Based on the findings of our thorough examination, a recommended scheme made up of HMg, HMcc, the electro-thermal membrane heating mode (HMef), the natural gas boiler room regional central heating mode (HMgrc) and the natural gas boiler room decentralized heating mode (HMgrd) was established. The recommended scheme can provide a theoretical basis for the implementation of clean heating policies in Northeast China.

Impatience and Modern Society

Abstract: Impatience is a defining aspect of the modern world and its identity, as is starkly exemplified in the emphasis on technology. Itis the central mode along which individual and social life areorganized. In contrast, for Mahatma Gandhi patience is the crucial category for healthy individual and social existence.

Standing out from the crowd: When and why color complexity in social media images increases user engagement

Firms increasingly rely on images to drive user engagement with their social media content. However, evidence is limited on when and why image characteristics can draw social media users’ attention and increase engagement. In this research, the authors theorize that color complexity in images can serve as an external cue that draws social media users’ attention and provokes a shift from the peripheral processing mode to the central processing mode. This shift can result in deeper processing of the social media post that features the image, thus increasing the likelihood of the users’ engagement with the post. They further reveal heterogeneity in the effect of color complexity due to the time of day when the users are exposed to the image, image height, and sentiment and complexity in the text accompanying the image. The results are consistent across an empirical analysis of two proprietary Facebook datasets from distinct industries and time periods and confirmed by two biometric eye-tracking experiments that provide process evidence. The findings have important implications for both content marketers and academics as they seek to identify content features that can maximize user engagement on social media.

FedSTN: Graph Representation Driven Federated Learning for Edge Computing Enabled Urban Traffic Flow Prediction

Predicting traffic flow plays an important role in reducing traffic congestion and improving transportation efficiency for smart cities. Traffic Flow Prediction (TFP) in the smart city requires efficient models, highly reliable networks, and data privacy. As traffic data, traffic trajectory can be transformed into a graph representation, so as to mine the spatio-temporal information of the graph for TFP. However, most existing work adopt a central training mode where the privacy problem brought by the distributed traffic data is not considered. In this paper, we propose a Federated Deep Learning based on the Spatial-Temporal Long and Short-Term Networks (FedSTN) algorithm to predict traffic flow by utilizing observed historical traffic data. In FedSTN, each local TFP model deployed in an edge computing server includes three main components, namely Recurrent Long-term Capture Network (RLCN) module, Attentive Mechanism Federated Network (AMFN) module, and Semantic Capture Network (SCN) module. RLCN can capture the long-term spatial-temporal information in each area. AMFN shares short-term spatio-temporal hidden information when it trains its local TFP model by the additive homomorphic encryption approach based on Vertical Federated Learning (VFL). We employ SCN to capture semantic features such as irregular non-Euclidean connections and Point of Interest (POI). Compared with existing baselines, several simulations are conducted on practical data sets and the results prove the effectiveness of our algorithm.

Large-Scale Distribution and Variations of Active Salt-Finger Double-Diffusion in the Western North Pacific

Abstract Large-scale distribution and variations in active salt fingers (SF) in the western North Pacific were examined by detecting the active SF with a vertical density ratio Rρ = 1–2 at depths of 10–300 m using a monthly gridded hydrographic dataset from 2001 to 2016. The active SF is distributed most frequently in March along 40°N around the Subarctic Boundary (SAB), where the mixed layer deepens northward and corresponds to the Central Mode Water formation site with a density from +0.02σθ to +0.2σθ of surface density and mainly in 26.1–26.4σθ. This active SF along 40°N underwent seasonal variation and decayed rapidly from March to August from the shallower and less dense parts of the active SF with increasing mean density. The features of the active SF in March are consistent with the hypothesis that surface water with a horizontal density ratio RL = 1–2 is subducted and vertically superposed, resulting in an active SF. The mean density of the active SF in March is well correlated with the surface density with RL = 1–2, and both mean densities showed a decreasing trend from 2001 to 2016, following the surface warming trend (∼0.057°C yr−1) in the surface water with RL = 1–2. Large year-to-year variations in the active SF in March are explained by both horizontal and vertical extensions, and can be reproduced by four conditions: 1) from 1°N to 3°S of SAB, 2) RL = 1–2, and 3) northward deepening of the mixed layer depth, and 4) the part with a density from +0.02σθ to +0.2σθ of surface density. Significance Statement It has been recognized that salt-finger (SF) double-diffusive convection is not active in the western North Pacific Ocean. This study demonstrated the distribution and seasonal/interannual variations of active SF in the western North Pacific for the first time: the formation of active SF along 40°N in 140°E–180° around the Subarctic Boundary in March and rapid decay until August, and large year-to-year variations of vertical and horizontal extensions with density decreasing trend. This study also proposed a formation mechanism that is relevant to the active SF density decrease and warming trend in the western North Pacific.

Alzheimer's Disease Genetic Influences Impact the Associations between Diet and Resting-State Functional Connectivity: A Study from the UK Biobank.

Red wine and dairy products have been staples in human diets for a long period. However, the impact of red wine and dairy intake on brain network activity remains ambiguous and requires further investigation. This study investigated the associations between dairy and red wine consumption and seven neural networks' connectivity with functional magnetic resonance imaging (fMRI) data from a sub-cohort of the UK Biobank database. Linear mixed models were employed to regress dairy and red wine consumption against the intrinsic functional connectivity for each neural network. Interactions with Alzheimer's disease (AD) risk factors, including apolipoprotein E4 (APOE4) genotype, TOMM40 genotype, and family history of AD, were also assessed. More red wine consumption was associated with enhanced connectivity in the central executive function network and posterior default mode network. Greater milk intake was correlated with more left executive function network connectivity, while higher cheese consumption was linked to reduced posterior default mode network connectivity. For participants without a family history of Alzheimer's disease (AD), increased red wine consumption was positively correlated with enhanced left executive function network connectivity. In contrast, participants with a family history of AD displayed diminished network connectivity in relation to their red wine consumption. The association between cheese consumption and neural network connectivity was influenced by APOE4 status, TOMM40 status, and family history, exhibiting contrasting patterns across different subgroups. The findings of this study indicate that family history modifies the relationship between red wine consumption and network strength. The interaction effects between cheese intake and network connectivity may vary depending on the presence of different genetic factors.

Investigating the power consumption for the intensification of gas dispersion in a dual coaxial mixer containing yield-pseudoplastic fluids

Coaxial mixers with double central impellers and an anchor have demonstrated promising results in the intensification of gas dispersion in complex fluids. While previous studies have evaluated power consumption for gas dispersion in pseudoplastic fluids, no investigation has been conducted on aerated dual coaxial mixers containing pseudoplastic fluids with yield stress. This study aimed to evaluate the power consumption of the aerated double coaxial mixer under various operating conditions, including anchor and central impeller speed, rotational mode, pumping direction, and aeration rate. Experimental power consumption measurements were performed for both gassed and ungassed systems. Our findings showed that the anchor power contributed substantially less to overall power consumption than the central impellers. The counter-rotational mode used more power than the co-rotational mode due to the opposing flow created by the rotation of the central impellers and anchor impeller. The co-rotational mode had a higher relative power demand (RPD) than the counter-rotational mode, with the upward pumping mode of the central impellers yielding the highest RPD values. The modified Jamshidzadeh's correlation successfully predicted the impact of the anchor speed, central impeller speed, and aeration rate on power consumption for the investigated double coaxial mixers containing the xanthan gum solution.

Research and Experiment on a Bionic Fish Based on High-Frequency Vibration Characteristics.

This paper takes the high-frequency vibration characteristics of a bionic robot fish as the research object. Through research on the vibration characteristics of a bionic fish, we quantified the role of voltage and beat frequency in high-speed and stable swimming. We proposed a new type of electromagnetic drive. The tail is made of 0° silica gel to simulate the elastic characteristics of fish muscles. We completed a series of experimental studies on the vibration characteristics of biomimetic robotic fish. Through the single-joint fishtail underwater experiment, the influence of vibration characteristics on parameters during swimming was discussed. In terms of control, the central mode generator control method (CPG) control model is adopted, and a replacement layer is designed in combination with particle swarm optimization (PSO). By changing the elastic modulus of the fishtail, the fishtail resonates with the vibrator, and the swimming efficiency of the bionic fish is improved. Finally, through the prototype experiment, it is found that the bionic robot fish can achieve high-speed swimming through high-frequency vibration.

Lattice-dynamics study of Raman-active modes in LaTiO3

The lattice dynamics plays an important role in the determining the orbital and magnetic ordering phenomena in rare-earth (R) RTiO3 titanates. In the present study, the assignment and vibrational character of Ag and B2g-symmetry phonons observed in the Raman spectra of LaTiO3 crystal is verified by shell-model calculations of eigenfrequencies, relative intensities, and eigenvector components of the normal modes. The eigenvector pattern of the Ag mode located around the most pronounced central mode at 296cm−1 is turned out to be in full agreement with the La–O covalency in LaTiO3, where the concomitant GdFeO3-type distortion is decisive. The GdFeO3-type mode is located in the close proximity to the Jahn-Teller (JT) tetragonal E-type Qε mode. An interplay between the R–O covalency and JT effects can determine the subtle conditions for the electronic ground state of the Ti3+ ion and associated orbital and magnetic ordering phenomena in RTiO3 titanates.

Zonally Asymmetric Multidecadal Variability of the North Pacific Subtropical Fronts

Abstract The North Pacific Subtropical Fronts (STFs), accompanied by the eastward-flowing subtropical countercurrent, stretch from the western Pacific Ocean to the north of Hawaii. Previous work has detected different trends of the frontal position and strength between the western STF (WSTF; west of 180°) and the eastern STF (ESTF; east of 180°) in the past 40 years. However, whether the basin-scale STFs have zonally asymmetric variability on multidecadal time scales and what drives that change remain to be quantified. Our recent work has shown that the multidecadal variability of the WSTF is controlled by the Atlantic multidecadal oscillation via the subtropical mode water variability. The present study proposes that the variability of ESTF is modulated by the Pacific decadal oscillation (PDO) via the central mode water (CMW) variability, quasi synchronously on multidecadal time scales. During a PDO positive phase, the enhanced midlatitude westerly winds in the central North Pacific increase the local surface buoyancy loss and deepen the winter mixed layer, which enlarges the CMW formation and thus increases its volume. Meanwhile, accompanied by the southward-migrated outcropping zone, the main body of CMW shifts equatorward. In response to such CMW changes, the ESTF strengthens and shifts equatorward correspondingly. Conversely, during a PDO negative phase, the weakened midlatitude westerly winds in the central North Pacific decrease the local surface buoyancy loss and shallow the winter mixed layer, which reduces the CMW formation and thus decreases its volume. Meanwhile, accompanied by northward-migrated outcropping zone, the main body of CMW shifts poleward. In response to such CMW changes, the ESTF weakens and shifts poleward correspondingly. Our results reveal that the dominant factor controlling the low-frequency variability of the WSTF and ESTF is different, which renews the conventional picture that all of the STFs behave symmetrically, with important implications for the North Pacific climate variability.

Digital platform regulation: opportunities for information systems research

PurposeInformation Systems (IS) research has built up a considerable understanding of digital platform ecosystems, while policymakers worldwide are aiming to introduce platform regulations that seek to erode fundamental mechanisms of digital platforms. This viewpoint article provides an introduction to how platform regulation affects our current understanding of digital platform ecosystems and suggests opportunities for future research.Design/methodology/approachA detailed analysis of the effects of the European Union (EU) Digital Markets Act (DMA) on current findings of organizational, technical and economic IS platform research.FindingsGovernment regulations of digital platforms such as the DMA likely affect the central mode of operation of platforms in the scope of the regulation. The authors preconceive a major impact on platform openness, governance, steering the platform supply-side, modularity, nestedness, network effects, pricing and single-/multi-homing. In addition, the authors present opportunities for future research in each of these IS platform research streams.Originality/valueLandmark regulations implemented in the past, such as the General Data Protection Regulation (GDPR), caused paradigm changes that fertilized research opportunities in IS and beyond. This viewpoint article aims to nudge studies that examine the changed mode of operation of platforms following platform regulation.

Effect of H2 addition on the local extinction, flame structure, and flow field hydrodynamics in non-premixed bluff body stabilized flames

We examined the effect of hydrogen (H2) enrichment on the primary fuel methane (CH4) in a canonical non-premixed bluff-body stabilized burner operating under typical central jet-dominated flame mode. In the chosen mode of operation, globally, the flow field and flame feature three important successive spatial zones: the recirculation zone, the neck zone, and the jet-like flame zone. The flame is exposed to a higher stretch rate in the neck zone in such a configuration and eventually undergoes local extinction. Such local extinction and subsequent re-ignition/reconnection of broken flame branches have substantial implications for the hydrodynamic instability of the coaxial annular air shear layer. It is well known that H2 addition increases the flame extinction strain rate (κext) and thus alters the local extinction phenomenon. To understand this, we performed experiments at 0%, 10%, 20%, 30%, 50%, 80%, and 100% hydrogen proportion in the H2-CH4 blend. High repetition rate (5 kHz) Particle Image Velocimetry and OH Planar Laser Induced Fluorescence (PLIF) measurements are simultaneously implemented to gain quantitative insight into the flow field and flame structure. A detailed analysis performed over the instantaneous OH–PLIF datasets reveals the absence of local extinctions in flames with H2 enrichment &amp;gt;30% due to an increased extinction strain rate (κext). Furthermore, it is found that H2 enrichment plays a significant role in the reconnection/re-ignition of the broken flame branches formed during the local extinction. For instance, a high reconnection probability is observed in flames with an H2 addition of ≥20%. Consequently, variations in the mean reaction zone height are witnessed for different H2 enrichment levels. Further analysis of the influence of variation in reaction zone height on flow field hydrodynamics is explored using Proper Orthogonal Decomposition (POD) and Continuous Wavelet Transform (CWT). The results obtained from POD and CWT indicated the suppression of vortex shedding at the annular air shear layer for H2 addition greater than 20% and irregular wrinkling of flame fronts. Thus, they quantified the beneficial effect of H2 addition in turbulent flame stabilization.

Influence of winter natural ventilation on thermal environment of university dormitories under central heating mode in severe cold regions of China

The indoor thermal environment impacts people’s health, while it can be adjusted by natural ventilation. However, studies on the effects of winter natural ventilation on the thermal environment in severe cold regions are minimal. Through field measurements in university dormitories in winter in Shenyang, China, this study explored, under the central heating mode, the thermal environment differences in different orientations of the dormitory and its different indoor positions under natural ventilation and the influence of window opening area and duration on the thermal environment. The results show that under winter natural ventilation, the air temperature, mean radiation temperature, and adaptive predicted mean vote (APMV) of dormitories facing different orientations were mainly affected by the direct solar radiation reception. When the ventilation duration reached 15mins, with the ratio of window opening area to a ground area of 0.05, 0.11, and 0.16, the APMV decreased by about 0.35, 0.5, and 1, respectively.

Subsurface dispersion path and travel time of radiocesium from Fukushima by Mode Water

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March 11, 2011 resulted in the release of immense amounts of radioactive materials into the ocean. However, the dispersion of radioactive materials in the subsurface has not yet been clarified due to the spatiotemporal limitation of observations. Thus, herein, a tracer experiment was implemented using a three-dimensional numerical model to estimate the dispersion path of 137Cs released directly from the FDNPP and its travel time in the subsurface of the North Pacific Ocean from 2011 to 2020. The results show that the subsurface 137Cs spreads by two mode waters, namely, Sub-Tropical Mode Water (STMW) and Central Mode Water (CMW). Subsurface 137Cs primarily spreads clockwise in the sub-tropical region, while a portion driven by STMW is dispersed southward. The clockwise dispersion path of 137Cs released into the ocean by STMW is relatively shallower and inward than that by CMW. The 137Cs that was spread clockwise reached the east of Taiwan and the Philippines via STMW and CMW nine years after the accident, respectively. The model described in this study is applicable for estimating the water path and travel time of tritium water planned to be discharged from Fukushima.