Global Fit Research Articles

Trap Depth Distribution Determines Afterglow Kinetics: A Local Model Applied to ZnGa2O4:Cr3.

Persistent luminescence materials have applications in diverse fields such as smart signaling, anticounterfeiting, and in vivo imaging. However, the lack of a thorough understanding of the precise mechanisms that govern persistent luminescence makes it difficult to develop ways to optimize it. Here we present an accurate model to describe the various processes that determine persistent luminescence in ZnGa2O4:Cr3+, a workhorse material in the field. A set of rate equations has been solved, and a global fit to both charge/discharge and thermoluminescence measurements has been performed. Our results establish a direct link between trap depth distribution and afterglow kinetics and shed light on the main challenges associated with persistent luminescence in ZnGa2O4:Cr3+ nanoparticles, identifying low trapping probability and optical detrapping as the main factors limiting the performance of ZnGa2O4:Cr3+, with a large margin for improvement. Our results highlight the importance of accurate modeling for the design of future afterglow materials and devices.

Unraveling the Structure and Dynamics of Ac-PHF6-NH2 Tau Segment Oligomers.

The aggregation of the proteins tau and amyloid-β is a salient feature of Alzheimer's disease, the most common form of neurodegenerative disorders. Upon aggregation, proteins transition from their soluble, monomeric, and functional state into insoluble, fibrillar deposits through a complex process involving a variety of intermediate species of different morphologies, including monomers, toxic oligomers, and insoluble fibrils. To control and direct peptide aggregation, a complete characterization of all species present and an understanding of the molecular processes along the aggregation pathway are essential. However, this is extremely challenging due to the transient nature of oligomers and the complexity of the reaction networks. Therefore, we have employed a combined approach that allows us to probe the structure and kinetics of oligomeric species, following them over time as they form fibrillar structures. Targeting the tau protein peptide segment Ac-PHF6-NH2, which is crucial for the aggregation of the full protein, soft nano-electrospray ionization combined with ion mobility mass spectrometry has been employed to study the kinetics of heparin-induced intact oligomer formation. The oligomers are identified and characterized using high-resolution ion mobility mass spectrometry, demonstrating that the addition of heparin does not alter the structure of the oligomeric species. The kinetics of fibril formation is monitored through a Thioflavin T fluorescence assay. Global fitting of the kinetic data indicates that secondary nucleation plays a key role in the aggregation of the Ac-PHF6-NH2 tau segment, while the primary nucleation rate is greatly accelerated by heparin.

The multiple mediation impact of adolescents' physical fitness and cognitive perceptions on their objective measures – The Cogni-Action Project

ObjectiveTo establish whether physical fitness and cognitive self-perceptions act as mediators in the link between global fitness and cognitive performance measured objectively in adolescents. We also compared differences across sex. MethodsA total of 1296 adolescents (50 % girls) from grades 5 to 8 (ages 10–14) participated in this cross-sectional study. The ALPHA-fitness test battery assessed physical fitness, comprising cardiorespiratory, speed-agility, and muscular fitness components. We used the 1–5-point International Fitness Scale for physical fitness self-perception, and the 1–10 scale for cognitive performance self-perception. Objective cognitive performance was assessed using a neurocognitive battery consisting of eight tasks. Using principal component analysis, these tasks were grouped into three domains: attention, working memory, and problem solving. We examined three serial mediation models adjusted for sex, standardized body mass index, maturation, and school vulnerability index. ResultsPhysical fitness and cognitive self-perceptions mediated the effects on attention (B = .0027, CI = .0011 to .0047), memory (B = .0025; CI = .0003 to .0055 and B = .0035; CI = .0009 to .0063), and problem-solving (B = −.0137; CI = −.0231 to −.0052 and B = .0072; CI = .0043 to .0106). By sex, boys showed mediation in all domains, while girls only showed mediation in problem-solving. ConclusionsAdolescents' perceptions play a crucial and positive mediating role in linking objective measures of physical fitness to cognitive performance outcomes, particularly when self-perceptions of physical fitness and cognition are considered together. Therefore, educating families and school/health environments about the importance of adolescent perceptions, while fostering self-awareness and reinforcing their capabilities, is essential.

Toward a more culturally nuanced approach to assessing athletic and exercise identities in sport psychology research: a confirmatory factor analysis approach with South Korean male student-athletes

ABSTRACT The identities of “athlete” and “exerciser” share conceptual similarities but can be differentiated by the ways in which their respective objectives, motivations, and intentions significantly diverge. However, there is a gap in the literature addressing the ambiguity and inconsistent use of these terms in the context of South Korea. The linguistic discrepancy in how these terms are conceptualised and operationalised has important implications for the study of athletes’ long-term health and well-being, where a nuanced perspective on identity is necessary for understanding physical activity behaviour and health outcomes through the transition out of competitive sport. Therefore, the purpose of this study was to refine the terminology used in the previously translated versions of the Athletic Identity Measurement Scale and Exercise Identity Scale and examine whether refined questionnaires appropriately represent similar but distinct concepts. Using software program R, this aim was addressed through a two-factor confirmatory factor analysis of the measurement scales within a sample of South Korean male student-athletes (N = 232, Mage = 19.93 ± 1.22 years). Global fit indices of the final model demonstrated acceptable fit χ2 (101) = 208.512, p < .01, CFI = .95, RMSEA = .07 (90% Confidence Interval: .06 – .08), SRMR = .06 and the local fit indices further supported convergent and discriminant validity of the scales within the sample. Recognition of cultural differences and nuances related to the terms “athlete” vs. “exerciser” and “sport” vs. “exercise” is important for fostering a comprehensive understanding of these identities within sport and exercise psychology research.

Contribution of dual-tasking to social participation in persons with multiple sclerosis: A structural equation modeling approach

IntroductionThis study aimed to explore the patterns of association between dual-tasking, cognition, ambulation disability, fatigue, and self-efficacy and their pathways in predicting social participation in persons with multiple sclerosis (MS). MethodsAdults with MS (n = 1162) completed an online survey. Social participation was assessed by the Quality of Life in Neurological Disorders. The Dual-task Impact on Daily-Living Activities Questionnaire, Multiple Sclerosis Walking Scale-12v2, and Modified Fatigue Impact Scale measured dual-tasking, ambulation, and fatigue, respectively. Fall Efficacy Scale-International and Self-Efficacy for Community Mobility were assessed and modeled as a latent variable for efficacy. ResultsThe correlation matrix showed significant associations of social participation with dual-tasking, cognition, ambulation, efficacy, and fatigue (all p < 0.001) and interrelationships among the independent variables (p < 0.05). The final model showed excellent global model fit (CFI = 0.99, TLI = 0.96), with all variables significantly predicting social participation either directly or indirectly. Efficacy significantly mediated the effects of dual-tasking (β=-0.32, p < 0.001) and ambulation disability (β=-0.42, p < 0.001) on social participation. ConclusionThis study indicated that dual-tasking, ambulation disability, fatigue, and efficacy play important roles in social participation in persons with MS. The findings can help provide insight into factors that may underpin social participation and offer targets for interventions in persons with MS.

Extending global fits of 4D Composite Higgs Models with partially composite leptons

We perform the first convergent Bayesian global fits of 4D Composite Higgs Models with partially-composite third generation quarks and leptons based on the minimal SO(5) → SO(4) symmetry breaking pattern. We consider two models with the τ lepton and its associated neutrino in different representations of SO(5). Fitting each model with a wide array of experimental constraints allows us to analyse the Bayesian evidence and currently-observed fine-tuning of each model by calculating the Kullback-Leibler divergence between their respective priors and posteriors. Notably both models are found to be capable of satisfying all constraints simultaneously at the 3σ level at scales of < 5 TeV. From a Bayesian viewpoint of naturalness the model with leptons in the 14 and 10 representations is preferred over those in the 5 representation due to its lower fine-tuning. Finally, we consider the experimental signatures for the preferred parameters in these models, including lepton partner decay signatures and gluon-fusion produced Higgs signal strengths, and discuss their potential phenomenology at future high-luminosity LHC runs.

Bayesian method for fitting the low-energy constants in chiral perturbation theory

The values of the low-energy constants (LECs) are very important in the chiral perturbation theory. This paper adopts a Bayesian method with the truncation errors to globally fit eight next-to-leading order (NLO) LECs Lir and next-to-next-leading order (NNLO) LECs Cir. With the estimation of the truncation errors, the fitting results of Lir in the NLO and NNLO are very close. The posterior distributions of Cir indicate the boundary-dependent relations of these Cir. Ten Cir are weakly dependent on the boundaries and their values are reliable. The other Cir are required more experimental data to constrain their boundaries. Some linear combinations of Cir are also fitted with more reliable posterior distributions. If one knows some more precise values of Cir, some other Cir can be obtained by these values. With these fitting LECs, most observables provide a good convergence, except for the πK scattering lengths a03/2 and a01/2. An example is also introduced to test the improvement of the method. All the computations indicate that considering the truncation errors can improve the global fit greatly, and more prior information can obtain better fitting results. This fitting method can be extended to the other effective field theories and the perturbation theory.

Refined determination of the weak mixing angle at low energy

The weak mixing angle is a fundamental parameter of the electroweak theory of the standard model whose measurement in the low-energy regime is still not precisely determined. Different probes are sensitive to its value, including atomic parity violation, coherent elastic neutrino-nucleus scattering, and parity-violating electron scattering on different nuclei. In this work, we attempt for the first time to combine all these various determinations by performing a global fit that also takes into account the unavoidable dependence on the experimentally poorly known neutron distribution radius of the nuclei employed, for which a new measurement using proton-cesium elastic scattering became available. By using all present direct determinations of the neutron distribution radius of cesium, we find sin2ϑW=0.2396−0.0019+0.0020, which should supersede the previous value determined from atomic parity violation on cesium. When including electroweak only, but also indirect, determinations of the neutron distribution radius of cesium, the uncertainty reduces to 0.0017, maintaining the same central value and showing excellent agreement independently of the method used. Published by the American Physical Society 2024

SIMUnet: an open-source tool for simultaneous global fits of EFT Wilson coefficients and PDFs

We present the open-source SIMUnet code, designed to fit Standard Model Effective Field Theory (SMEFT) Wilson coefficient alongside Parton Distribution Functions (PDFs) of the proton. SIMUnet can perform SMEFT global fits, as well as simultaneous fits of the PDFs and of an arbitrarily large number of SMEFT degrees of freedom, by including both PDF-dependent and PDF-independent observables. SIMUnet can also be used to determine whether the effects of any New Physics models can be fitted away in a global fit of PDFs. SIMUnet is built upon the open-source NNPDF code and is released together with documentation, and tutorials. To illustrate the functionalities of the new tool, we present a new global analysis of the SMEFT Wilson coefficients accounting for their interplay with the PDFs. We increment our previous analysis of the LHC Run II top quark data with both (i) the Higgs production and decay rates data from the LHC, and (ii) the precision electroweak and diboson measurements from LEP and the LHC.

(Invited) Ultrafast Excited Electron Relaxation in Triply Fused Ni(II) Porphyrin-Nanographene Conjugates for Energy Conversion

Porphyrins are appealing building blocks for solar energy applications, although their photosensitization capability is limited by their large optical energy gap, resulting in a mismatch in absorption for efficient harvesting of the solar spectrum. Porphyrin π-extension by edge-fusing with nanographenes can be employed to narrow their optical energy gap, enabling the development of porphyrin-based panchromatic dyes with an optimized energy onset for solar energy conversion in dye-sensitized solar fuel and solar cell configurations. Metalloporphyrin-nanographene conjugates based on open-shell transition metals, such as Ni(II), exhibit panchromatic absporption covering the entire visible and part of the near-IR spectral range. Dispite this interesting property, they exhibit fast excited-state electronic relaxation across the Ni d levels, which hampers harnessing photoexcited electrons to trigger photophysical or photochemical reactions. In this work, we shed light into the underlying mechanism behind fast non-radiative relaxation in these systems. Variable temperature transient absorption and global fit analysis are combined with time-dependent density functional theory to produce a picture of the relevant excited states and underlying relaxation pathways in the conjugates. At room temperature, photoexcitation to the lowest S1* energy level is followed by vibrational cooling in 1-2 ps, and intersystem crossing in > 10 ps, setting a short temporal window wherein a small fraction of relaxed singlets decay to the ground state. Following intersystem crossing and triplet internal conversion, triplets relax rapidly to the ground state (S0) in few tens of picoseconds. By performing measurements at low temperature, we provide evidences for the interplay of a lowest terminal triplet level with > 1 ns lifetime which acts as a bottleneck, and a sloped conical intersection to S0* which is thermally accessible at room temperature from the former energy level. The overall triplet decay is dictated by the contributions that fall along these two photophysical branches. This observation bears significance in understanding how nanographene functionalization leads to a profound effect, opening avenues for potential applications in Optoelectronics and related fields.[1] Garcia-Orrit, S., Vega-Mayoral, V., Chen, Q., Serra, G., Paternò, G. M., Cánovas, E., Narita, A., Müllen, K., Tommasini, M., Cabanillas-González, J., Nanographene-Based Decoration as a Panchromatic Antenna for Metalloporphyrin Conjugates. Small 2023, 19, 2301596.[2] Garcia-Orrit, S. et al., in preparation Figure 1

Redshift constrain of BL Lac PKS 1424+240

ABSTRACT In the period between 2009 and 2015, several very high-energy (VHE $&amp;gt; 100$ GeV) gamma-ray flaring events from the BL Lac object PKS 1424+240 were observed by the Cerenkov telescopes VERITAS and MAGIC. It had uncertain redshift (z) and using spectroscopical measurement, Paiano et al. (2017) found it to be $z=0.604$. Using four different extragalactic background light (EBL) models and the photohadronic model, nine independently observed VHE gamma-ray spectra of PKS 1424+240 are analysed and a global $\chi ^2$ fit is performed on all observations to estimate the best-fitting value for the redshift for each EBL model. Confidence levels (CL) intervals for the redshift are also estimated using all the EBL models. This method is tested by comparing our analysis with the observed value. It is shown that the photohadronic scenario provides an excellent description of all the observed spectra. It is found that the EBL model of Dominguez et al. (2011) is the one that provides the most restrictive limits on the redshift of PKS 1424+240, but in our analysis, $z=0.604$ lies within the $3\sigma$ CL interval of the EBL model of Saldana-Lopez et al. (2021).

Dynamic formulation and inertia fast estimation of a 5-DOF hybrid robot

As the main driving mechanism of a hybrid robot, the parallel mechanism is a nonlinear time-varying system. The load inertia of its actuated joints changes with the configuration of the robot. Analyzing and fitting the inertia variation is of great significance to the design and control of hybrid robots. By taking a hybrid robot named TriMule as an example, the variation of load inertia of each actuated joint in the whole workspace is first revealed based on the dynamic analyses of the robot. Then two methods based on the circular and elliptical membership are proposed to calculate fitted inertia over the whole workspace using inertia information at a few configurations. Finally, the fitting methods of the two membership functions are compared and discussed. The results show that the maximum value and global mean value of the fitting error of the elliptical membership method are 39.18% (51.23%) and 65.79% (81.25%) for actuated joint-1 (joint-2 and joint-3) lower than those of circular membership method, which promise a better global fitting accuracy. The proposed method can be used to estimate the joint load inertia or other control variables affected by inertia in a quick manner, allowing the algorithm to be easily integrated into the robot control system.

High-frequency vibration of beveled crystal plates by using subregional geometric fitting method

The beveling process is an important process in the manufacturing of resonators, which has a significant impact on the frequency stability of resonators. Without understanding the frequency characteristics of the resonator after beveling, it is impossible to accurately design the beveled resonators. Thus, in order to investigate the vibration characteristics of AT-cut beveled resonators, we investigated the high-frequency vibration in this work by using the subregional geometric fitting method (SGFM) based on Mindlin’s plate theory. Quartz crystal plates with nonuniform thicknesses are partitioned into three regions and each region is fitted by using the polynomial functions based on the measured geometric morphology data. The governing equations are obtained based on Mindlin’s two-dimensional theory and the coupled vibrations are further solved using the partial differential equation module of COMSOL. In the numerical calculation, we compare the results obtained by the SGFM with those obtained by the global fitting method and the measured data. The accuracy and effectiveness of the SGFM are also verified. It is found that the frequencies obtained by the SGFM are slightly higher than the frequencies obtained by the global fitting method, and the results of SGFM are closer to the measured results. Meanwhile, as the beveling time increases, the frequency increases and the energy trapping effect becomes more significant. The proposed method can significantly improve the computational efficiency of thickness-shear vibration while ensuring accuracy. It is expected to provide a new geometric fitting method for the analysis of beveled crystal resonators.

Hints of entanglement suppression in hyperon-nucleon scattering

Hyperon (Y=Σ,Λ)-nucleon (N=n,p) interactions are crucial for understanding the existence of neutron stars heavier than two solar masses. Amid renewed experimental efforts, we study YN scatterings from the perspective of quantum information, focusing on whether spin entanglement is suppressed in the s-wave channel, which is observed in np scattering and leads to enhanced global symmetries. Using global fits of phase shifts from experimental data, we find hints of entanglement suppression among the eight flavor channels in the strangeness S=−1 sector, similar to the np case. One exception is the Σ+p channel, where conflicting global fits lead to inconclusive outcome. We then propose “quantum” observables in Σ+p scattering to help resolve the differing global fits.

Critical consciousness among undocumented immigrant college students: Responding to cultural stress and psychological distress.

Cultural stress is experienced by undocumented students when they encounter discrimination in higher education and society. In response, undocumented students engage in critical consciousness, while simultaneously experiencing psychological distress. A conceptual model is introduced to describe the links between cultural stress, critical consciousness development, and psychological distress. One hundred seventy-one undocumented college students were recruited to participate in this study and completed measures of cultural stress (discrimination). They also completed measures of psychological distress, critical consciousness, and social justice self-efficacy and outcome expectations. The proposed model was tested for global fit and path analysis in structural equation modeling. Indirect effects were probed to assess the mediating role of critical consciousness and psychological distress. The model fit the data excellently. Greater discrimination was associated with higher critical consciousness, which in turn was associated with elevated social justice self-efficacy and outcome expectations. Additionally, higher discrimination was also linked to greater psychological distress. The link between cultural stress and critical consciousness was not explained by psychological distress. This research expands theory by articulating the adaptive ways undocumented students respond to the conditions that cause cultural stress and psychological distress. This aligns with a growing literature documenting the psychology of undocumented immigrants' activism and advocacy. Findings may inform interventions by higher education institutional agents and research to offset cultural stress and psychological distress. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Higgs boson precision analysis of the full LHC run 1 and run 2 data

We perform global fits of the Higgs boson couplings to the full Higgs datasets collected at the LHC with the integrated luminosities per experiment of approximately 5/fb at 7 TeV, 20/fb at 8 TeV, and up to 139/fb at 13 TeV. Our combined analysis based on the experimental signal strengths used in this work and the theoretical ones elaborated for our analysis reliably reproduce the results in the literature. We reveal that the LHC Higgs precision data are no longer best described by the Standard Model (SM) Higgs boson taking account of extensive and comprehensive CP-conserving and CP-violating scenarios found in several well-motivated models beyond the SM. Especially, in most of the fits considered in this work, we observe that the best-fitted values of the normalized Yukawa couplings are about 2σ below the corresponding SM ones with the 1σ errors of 3%–5%. On the other hand, the gauge-Higgs couplings are consistent with the SM with the 1σ errors of 2%–3%. Incidentally, the reduced Yukawa couplings help to explain the excess of the H→Zγ signal strength of 2.2±0.7 recently reported by the ATLAS and CMS collaborations. Published by the American Physical Society 2024

Deep learning with local spatiotemporal structure preserving for soft sensor development of complex industrial processes

Data-driven soft sensors have emerged as indispensable tools for predicting quality variables in complex industrial processes because of their cost-effectiveness and ease of maintenance. In particular, soft sensors based on deep learning have been utilized in extensive research and successful applications in recent years. However, traditional deep learning methods capture hierarchical data features by minimizing global fitting errors, neglecting the local structural characteristics implied in the original data. In this paper, we propose a new deep learning method for soft sensor development. Utilizing autoencoders as the foundational architecture of our network, a new semisupervised strategy is adopted for layerwise pretraining optimization. On the one hand, more representative data features are extracted by maintaining the local spatiotemporal structure of the data; on the other hand, layer-by-layer supervised learning is employed to identify the critical features that are aligned with the ultimate task, which aids in obtaining the optimal network parameters and improving the resulting prediction accuracy. Subsequently, a local spatiotemporal structure-preserving stacked semisupervised autoencoder (LSP-SuAE) is established. To evaluate the feasibility and effectiveness of the proposed approach, experiments are carried out in a real industrial process. A soft sensor based on the LSP-SuAE is developed to predict the rate of ethylbenzene conversion during the dehydrogenation of styrene. The experimental results demonstrate that, compared to five other common or similar data-driven modeling methods, LSP-SuAE exhibits higher prediction accuracy and better stability.

Global lepton flavour violating constraints on new physics

We perform a global analysis of the bounds from charged lepton flavour violating observables to new physics. We parametrize generic new physics through the effective field theory formalism and perform global fits beyond the common one-operator-at-a-time analyses to investigate how much present data is able to constrain the full parameter space. We particularly focus on leptonic and semileptonic operators with light quarks, identifying unbounded flat directions, detailing how many are present and which operators are involved. The analysis is performed in the general LEFT formalism, which contains all possible low-energy effective operators relevant for lepton flavour violation, as well as in more restricted scenarios, when operators come from a SMEFT completion. We find that flat directions play no role in the fully leptonic four-fermion operators. Conversely, they significantly hinder the ability to derive global bounds on semileptonic operators, with several flat or at least very poorly constrained directions preventing to fully constrain the parameter space. These results are particularly affected by the proper inclusion of uncertainties in the parameters describing μ-e\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu -e$$\\end{document} conversion, which decrease the number of well-constrained directions in operator space when treated as nuisance parameters in the fit. While present data is able to provide global constraints on all operators only in the more restricted scenarios we investigated, very strong correlations among the parameters must exist to avoid conflict with the different observables. We provide correlation matrices approximating our full results as a useful tool to compare present data with particular UV completions.

A lepton model with nearly Cobimaximal mixing

Cobimaximal mixing predicts π/4 and 3π/2 for the atmospheric angle and the Dirac CP-violating phase, respectively. These values are in tension with the neutrino global fits. If this pattern was behind the lepton mixings, then it would have to be broken. In that case, in this paper, we explore the S3 flavor symmetry within the B − L gauge model where the aforementioned scheme comes from the neutrino sector but the charged lepton contribution breaks the well known predictions so the mixing observables as well as the mee mass can be accommodated quite well according to the available data. Notably, the predicted regions for the Dirac CP-violating phase would allow us to test the model in future experiments.

Investigating early dark energy with new observations

This paper mainly presents updated constraints on several types of early dark energy (EDE) models proposed by V. Pettorino et al. using observations of cosmic microwave background radiation (CMB) from Planck satellite, the Pantheon Type Ia supernovae (SNIa) sample, and baryon acoustic oscillation (BAO) measurements. The results yield stringent upper limits on the constant EDE fraction parameter Ωe. While the present equation of state (EoS) of dark energy w0 in the EDE1 model suggests a mild tendency towards a value less than −1, these models remain compatible with the ΛCDM scenario. Partly as a result of this slight tendency towards phantom late-time physics, EDE1 model supports a higher Hubble constant value, potentially narrowing the Hubble tension gap. The global fitting results also align with the notion that the constraint ability on Ωe weakens when dark energy is present only over a limited period after last scattering. Furthermore, by using the formalism of Fisher information matrix, we forecast uncertainties in the measured parameters of EDE models from the next-generation “Stage 4” CMB (CMB-S4) experiment. Forecasted precision of w0 and Ωe surpasses certain prior works, and most other basic parameters exhibit significantly higher limit precision compared to Planck 2018 results within the ΛCDM framework. To confirm the presence of EDE within the EDE1∼EDE4 parameterization frameworks, further advancements in observations are crucial.