Fine Analysis Research Articles

AQcalc: A web server that identifies weak molecular interactions in protein structures.

Weak molecular interactions play an important role in protein structure and function. Computational tools that identify weak molecular interactions are, therefore, valuable for the study of proteins. Here, we present AQcalc, a web server (https://aqcalcbiocomputing.com/) that can be used to identify anion-quadrupole (AQ) interactions, which are weak interactions involving aromatic residue (Trp, Tyr, and Phe) ring edges and anions (Asp, Glu, and phosphate ion) both within proteins and at their interfaces (protein-protein, protein-nucleic acids, and protein-lipid bilayer). AQcalc identifies AQ interactions as well as clusters involving AQ, cation-π, and salt bridges, among others. Utilizing AQcalc we analyzed weak interactions in protein models, even in the absence of experimental structures, to understand the contributions of weak interactions to deleterious structural changes, including those associated with oncogenic and germline disease variants. We identified several deleterious variants with disrupted AQ interactions (comparable in frequency to cation-π disruptions). Amyloid fibrils utilize AQ to bury anions at frequencies that far exceed those observed for globular proteins. AQ interactions were detected three and five times more frequently than the hydrogen-bonded AQ (HBAQ) in fibril structures and protein-lipid bilayer interfaces, respectively. By contrast, AQ and HBAQ interactions were detected with similar frequencies in globular proteins. Collectively, these findings suggest AQcalc will be effective in facilitating fine structural analysis. As other web utilities designed to identify protein residue interaction networks do not report AQ interactions, wide use of AQcalc will enrich our understanding of residue interaction networks and facilitate hypothesis testing by identifying and experimentally characterizing these comparably weak but important interactions.

Experimental comparison of the flow-induced loading between a ducted bottom-mounted twin vertical axis tidal turbine at still and an unducted prototype

The FloWatt project aims to demonstrate the efficiency of the HydroQuest’s 2.5 MW-rated turbine for commercial farm deployment. The project is dedicated to develop an innovative design of a turbine for high energetic sites and to deploy seven vertical axis tidal turbines on the Raz Blanchard site, France. This technology has already been successfully developed in a previous project at a smaller scale on the Paimpol-Bréhat test site.
 Along the past three years, an important amount of work has been achieved to widely characterise the behaviour of the 1/20 scale 2-VATT similar to the 1MW-rated demonstrator. The turbine was tested in many different operating conditions in the Ifremer’s wave and current flume tank to reproduce full-scale conditions and turbine response (wide range of operating points and incident velocities, facing aligned and misaligned currents, with and without vertical velocity shear, with and without bathymetry generated turbulence, with and without surface waves following and against the current). Based on that experience, we gain confidence in the design process by comparing those experimental results to numerical and in-situ ones.
 
 After a quick presentation of the industrial development for the deployment of a pilot farm with the manufacture, installation and operation of 7 turbines on the Raz-Blanchard site, we will focus on the scientific development aiming to prepare large-scale deployments of the next generation of turbine. One important step is to compare the flow-induced loading between the 2 kinds of turbine (ducted and unducted) and to analyse environmental loads during survival conditions. To investigate those points, the behaviour of a 1/20 scale 2-VATT similar to the 2.5 MW-rated demonstrator is experimentally studied in a wide range of operating conditions: with and without vertical velocity shear, and with and without surface waves following and against the current. 
 In the paper, we will compare at 1/20 scale the behaviour of the two kinds of turbine: 1 MW-rated and 2.5 MW-rated turbines. The experiments have been done in the same basin, under the same experimental conditions. The databases are being processed before launching a fine physical analysis.

(Digital Presentation) Hydrothermal Electrodeposition of Molybdenum Sulfide Toward Electrochemical CO2 Reduction Catalysts

The search and development of efficient carbon dioxide (CO2) reduction reaction electrocatalysts is a hot topic in this era of global warming. Among material candidates for sustainable and cost−effective applications, metal sulfides have attracted attention as promising nature-inspired materials due to multiple adsorption sites which are enhanced by the covalent character of sulfur.Molybdenum sulfides (MoS2) is one of the trandition metal dichalcogenides (TMDs) and possesses three kinds of struture; namely, metastable octahedral structure with high electronic conductivity (1T), stable triangular prism structure with low electronic conductivity (2H) and insulating rhombohedral structure (3R). Among them, 1T phase has been widely applied as catalysts for various reactions such as electrochemical nitrogen reduction reaction and electro/photochemical hydrogen evolution reaction. Since the structure of MoS2 largely affect its catalytic and other material property, synthetic process to control their bulk and even local structure should be explored to expand their availability as functional materials. Especially, our previous work (J. Phys. Chem.C, 126, 2772, 2022) demonstrated that metal-sufur bonding length is one of the key parameter to control carbon monoxide production selectivity from electrochemical CO2 reduction.Here in this work, hydrothermal electrodeposition was applied to MoS2 synthesis to control their local structure. Recently, our group developed hydrothermal electrochemical flow reactor which enables the electrochemistry under hydrothermal condition with separate control of temperature and pressure. Using this reactor, hydrothermal electrodeposition of manganese oxides (MnO2) was conducted and samples exhibited higher electrochemical oxygen evolution activity than ones prepared with conventional methods. Also, the characterization results of electrodeposited MnO2 under hydrothermal condition showed the possiblity that morphology and lattice spacing can be controled by changing deposition temperature and pressure, respectively. Thus, we predicted our hydrothermal electrodeposition technique is useful to control the local structure of materials.The hydrothermal electrodeposition of MoS2 were conducted under various temperature and pressure conditions and those samples were characterized with X-ray diffraction (XRD). Also, the effect of the deposition temperature and pressure on sample local structure was examined with Pair Disribution Function analysis of XRD and Extended X-ray Absorption Fine Structure analysis using synchrotron radiation. The electrochemical CO2 reduction experiments using hydrothermally depositted MoS2 samples revealed that the product selectivity for CO2 reduction was changed with deposition pressure. Thus, we confirmed that our hydrothermal electrochemical deposition can be applicable to the synthesis of metal sulfide-based CO2 reduction electrocatalysts, whose local structures are tuned.

Fine multibubble analysis in the higher-dimensional Brezis–Nirenberg problem

For a bounded set \Omega \subset \mathbb{R}^N and a perturbation V \in C^1(\bar{\Omega}) , we analyze the concentration behavior of a blow-up sequence of positive solutions to -\Delta u_\varepsilon + \varepsilon V u_\varepsilon = N(N-2) u_\varepsilon^{\frac{(N+2)}{(N-2)}} for dimensions N \geq 4 , which are non-critical in the sense of the Brezis–Nirenberg problem. For the general case of multiple concentration points, we prove that concentration points are isolated and characterize the vector of these points as a critical point of a suitable function derived from the Green function of -\Delta on \Omega . Moreover, we give the leading-order expression of the concentration speed. This paper, with a recent one by the authors [arXiv:2208.12337, 2022] in dimension N = 3 , gives a complete picture of blow-up phenomena in the Brezis–Nirenberg framework.

Asymptotic behavior of Riemann solutions to a hyperbolic system arising from a traffic flow model

This paper is mainly concerned with the Riemann problem for a hyperbolic system arising from a traffic flow model, whose Riemann solutions are obtained constructively in terms of the fine analysis of elementary waves. Especially, the Dirac delta shock wave is involved in the Riemann solution at some specially designated initial data. Then, the limiting behavior of Riemann solutions is investigated carefully from the current system to the pressureless Euler system by sending the perturbed parameter tend to zero, in which more complicated nonlinear phenomena of cavitation and concentration than before can be observed and analyzed during this limiting process. Finally, several representative numerical examples are offered to confirm our theoretical results.

Carl Schmitt on the Transformations of the People in Modernity

Abstract This article argues that through the reinterpretation of the old theory of pouvoir constituant proposed by Sieyès, Carl Schmitt shows the impossibility of political modernity being anything other than authoritarian populism, whether by means of democratic or autocratic procedures. It is not that Schmitt's theory is authoritarian populism, but that modern politics, born out of the French Revolution, cannot be anything else. Schmitt's analyses of the idea of the people in political modernity in Dictatorship (1921), The Crises of Parliamentary Democracy (1923), Volksentscheid und Volksbegehren (1927), Constitutional Theory (1928), and State, Movement, People (1933) provide a fine analysis of the populist character of modernity. Something that those alive in the twenty-first century have been able to experience was theorized by Schmitt in an oracular way. Because of his keen insight he is still worth reading.

Short-term impact of tropical cyclones in Madagascar: evidence from nightlight data

ABSTRACT This paper explores the short-term effect of tropical cyclones on economic activity at a local level in Madagascar. To do so, we combine high-resolution spatial data about nightlight brightness and exposure to tropical cyclones with geographic information at the smallest administrative level in Madagascar, namely the Fokontany. Our findings reveal that exposure to tropical cyclones leads to an ambiguous economic response as proxied by nocturnal brightness during the first year after the shock. However, during the second year, nightlights clearly increase, leading to an overall beneficial effect of 5% just 2 years after the tropical cyclone. We then provide a finer analysis by interacting wind speed exposure with variables that capture many heterogenous dimensions of our data. This analysis shows that for Fokontany sharing specific characteristics, the short-run effect of tropical cyclones is negative. However, the positive effect of exposure in the second year emerges as a regular pattern in our analysis. Our empirical study is in line with economic mechanisms suggesting that after a period of contraction, the impacted economy rebounds beyond the counterfactual trend that would otherwise be observed in the absence of a shock.

Abstract P3122: Rap1gap2 Fine-mapping For Causal Variants Of Prevalent Ischemic Heart Disease Among Diverse Postmenopausal Women From The Women’s Health Initiative

Background: RAP1GAP2 is a GTP-ase activating protein that regulates secretion of dense granules from platelets at sites of endothelial damage, eliciting maximal platelet aggregation, a hallmark of ischemic events. Our published sex-stratified GWAS significantly associated RAP1GAP2 (Chr 17p13.3) variants with ischemic heart disease (IHD) case status and increased mortality risk among women but not men. We hypothesize that RAP1GAP2 genetic variation may demonstrate causal effects for the increased risk of IHD case status among postmenopausal women. Purpose: To fine-map RAP1GAP2 to identify causal markers for risk of IHD case status among racially and ethnically diverse postmenopausal women. Methods: We performed secondary analysis of 8,699 postmenopausal women from the Women’s Health Initiative (Observational cohort) who have publicly available genome-wide and densely imputed genotype data via NIH/dbGap (Affymetrix Affy 6.0). IHD case status was defined as prevalence of myocardial infarction, stroke, angina, congestive heart failure, peripheral arterial disease, or atherosclerotic interventional procedures at or prior to baseline; non-IHD controls were absent of all IHD criteria. PCA and Efficient Local Ancestry Inference (ELAI) were used to infer global and SNP-wise local ancestries. For each SNP, we performed SNP-wise logistic regression modeling, calibrating for the confounding effects of local and global ancestries and controlling for major cardiac risk factors, hormone replacement and cardiac medication exposure, IHD type (obstructive, nonobstructive), eGFR, education, income, and occupation. Results: Mean age 64.08 (±7.74) for a sample of 3,125 (36%) non-Hispanic Whites, 3,841 (44%) African Americans and 1,733 (20%) Hispanic Americans. We observed 1,932 IHD cases and 6,767 non-IHD controls. Novel PCA and ELAI uncovered strong spatial global population structure, varying ancestries, and ancestry-genotype correlations across genomic regions. Fine mapping analyses are underway and results will be available at time of presentation. Conclusions: Identifying sex- and ancestry-related causal genetic factors can serve as future targets for precision prevention of IHD among postmenopausal women.

Structure, microstructure and disorder in low temperature chemical vapor deposited SiC coatings

Chemical vapor deposited SiC coatings were investigated at different scales by X-Ray diffraction, Raman microspectroscopy and transmission electron microscopy. They were prepared under specific conditions explaining the various (micro)structures obtained. The deposits all have a columnar morphology with a preferential orientation and a faulted cubic structure. They differ in how disorder is incorporated in the structure. Fine XRD analyses and stacking fault density assessment by TEM revealed the one-dimensionally-disordered (ODD) polytype in the <111> textured coatings. The frequency and spatial distribution of stacking faults vary and sometimes locally generate periodic alpha sequences. A specific type of disorder was also identified where {111} planes are arranged parallel to the growth direction within the columns. These disorders, more energetic than stacking faults, induce multiple and particularly large Raman modes. Crystal distortions, such as dislocations, are localized at the ODD domain boundaries, which are frequently interrupted as they extend during the growth.

Study of the mechanism of inhibiting alkali-aggregate reaction and self-healing in concrete materials

Concrete is one of the most widely used materials in the world; however, several pathological manifestations can be associated with the design, execution, and selection of its constituent materials. Cracks, one of these pathological manifestations, are caused by the alkali-aggregate reaction (AAR). This is a chemical phenomenon in which silica, which is present in aggregate, reacts with alkali ions of the cement paste to produce an expansive silica-alkali gel. Herein, the clogging mechanism of the pathological cracks, which form during AAR, was investigated using a reference mortar trace, in order to select innocuous and reactive aggregates. Expansion in the mortar mix was examined using these two types of aggregates: (i) a potentially reactive aggregate, which can promote the formation of pathological cracks during AAR, and (ii) an innocuous aggregate to establish a reference trace without any expansive reaction. Subsequently, a concrete mix was characterized and reactivities of its constituents evaluated. In addition, fine and coarse granulometry analyses were performed. The concrete mix was dosed with the mortar mix, which comprised potentially reactive aggregate, and the bars were molded for the expansion tests. The crystalline mineral additive was added in these concretes to observe the clogging of the cracks. Comparative evaluation of the concrete mix, with and without reactive aggregate, suggested the occurrence of clogging because of the autogenous healing caused by chemical reactions, resulting in a reduction in the expansion of the concrete bars, with crystalline additive, at day 56.

Traveling waves and free boundaries arising in tumor angiogenesis

In a paper appeared in 2021, a mathematical model was developed for tumor invasion with vessel cooption, including a fine analysis of angiogenesis driven by chemotaxis. Numerical solutions in spherical symmetry revealed that a traveling wave sets in. Results were in agreement with experimental data. In the present paper, we introduce some nontrivial changes in the model and we further analyze the structure of the solutions as well as their dependence on some critical biological parameters, emphasizing for instance which are the most active zones where angiogenesis takes place. Moreover, we propose an alternative model characterized by the presence of a free boundary (playing the role of the invasion front), showing that the new formulation (which is advantageous from the computational point of view) matches the results of the previous model for some biologically significant range of the parameters.

A singular perturbation problem for mean field games of acceleration: application to mean field games of control

The singular perturbation of mean field game systems arising from minimization problems with control of acceleration is addressed, that is, we analyze the behavior of solutions as the acceleration costs vanishes. In this setting, the Hamiltonian fails to be strictly convex and coercive w.r.t. the momentum variable and, so, the classical results for Tonelli Hamiltonian systems cannot be applied. However, we show that the limit system is of MFG type in two different cases: we first study the convergence to the classical MFG system and, then, by a finer analysis of the Euler–Lagrange flow associated with the control of acceleration, we prove the convergence to a class of MFG systems, known as, MFG of control.

Chemical synthesis and crystallographic data on iron doped cubic ye'elimite

Pure powders of ye'elimite Ca4Al6-2xFe2xSO16 particles containing iron were synthesized by chemical route for the first time, the maximum of ye'elimite formed was obtained at 1250 °C for 1 h. The increase in iron content in the reaction system is accompanied by the increase on amount of the iron-stabilized cubic phase after calcination at sufficient temperature, at the expense of the orthorhombic phase until a concentration of x = 1.13 where only the cubic phase is detected. The presence of iron also causes the formation of ferritic phases. A protocol of elimination of the ferritic phases was proposed. This chemical treatment with sodium dithionite was applied to compositions containing a large majority of cubic ye'elimite and the isolation of cubic ye'elimite grains was successful. Thanks to very fine crystallographic analyses, the crystal structure of Ca4[(Al4.74Fe1.26)O12]SO4, a cubic ye'elimite doped only with Fe2O3, has been successfully determined for the first time.

Collaboration between Oil Development and Water/Power Consumption in High-Water-Cut Oilfields

Waterflooding is the main development technique used in the vast majority of oilfields in the world. However, as the waterflood oilfields enter the stages with (ultra-)high water cut, the water/power consumption per ton of oil remains unabatedly high. This paper presents a systematic analysis of the development stages and strategies of some typical waterflood oilfields in the world and proposes the necessity to establish a mode and technical system of collaboration between oil development and water/power consumption in mature oilfields with (ultra-)high water cut. Then, taking a pilot test area of an ultra-high-water-cut oilfield in northeastern China as an example, this paper investigates its development mode and water/power consumption; optimizes the technical strategies from the aspects of fine reservoir analysis, artificial lift system and surface gathering system; and predicts the application results. It is found that the optimizations of fine reservoir analysis and development plans effectively reduce the water consumption per ton of oil and have a certain but not remarkable contribution to the power consumption per ton of oil. Moreover, the optimizations of the artificial lift system and surface gathering system significantly reduce the power consumption per ton of oil. Under conditions of low production and low efficiency, the optimization of the artificial lift system greatly improves the energy-saving effect, which will be a focus of future research. Finally, this paper recommends measures for collaboration between oil development and water/power consumption in high-water-cut oilfields.

Initial stiffness of connection joining I-beam to concrete-filled multicellular steel tube wall

Concrete-filled multicellular steel tube (CF-MCST) wall is widely used in China in recent years. In the companion paper, the moment capacity of the connection joining an I-beam to a CF-MCST wall was studied. Realizing that the insight into the connection's stiffness would greatly benefit performing a fine structural analysis, this paper aims to propose a theoretical approach for approximating the rotational stiffness of the connection. Finite Element (FE) model is first established for analysis, which is validated by using the experimental results extracted from previous studies. In order to attain the stiffness resulting from the endplate and the wall individually, an additional companion FE model is employed, where the endplate's deformation is negligible by using an extreme great value for the Young's modulus of the endplate and the connection's rotation is therefore mainly attributed to the wall's local deformation near the connection. For the stiffness accounting for the deformation of the endplate, the stiffness accounting for the local deformation of the wall, and the connection's stiffness, parametric study is then performed via the validated FE models whose geometrical parameters falling into the range conventionally taken in the engineering. Based on the FE analysis results, the abstracted mechanical model is proposed, resulting in semi-empirical formulas where partial parameters are identified by the means of regression analysis. It is found that enlarging the geometrical parameters would improve the connection's stiffness. Among the parameters, the beam height has the most significant effects on the connection's stiffness. Accordingly, increasing the beam height first is suggested for the aim of enhancing the connection's stiffness. The comparison of the results obtained via the FE analyses and that obtained via the proposed theoretical approach shows a good agreement, and the error is <10% regarding the connection's stiffness.

Optimal incompatible Korn–Maxwell–Sobolev inequalities in all dimensions

We characterise all linear maps {mathscr {A}}:mathbb R^{ntimes n}rightarrow mathbb R^{ntimes n} such that, for 1le p<n, PLp∗(Rn)≤c(A[P]Lp∗(Rn)+CurlPLp(Rn))\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} \\left\\Vert P\\right\\Vert _{{\ ext {L}}^{p^{*}}(\\mathbb R^{n})}\\le c\\,\\Big (\\left\\Vert {\\mathscr {A}}[P]\\right\\Vert _{{\ ext {L}}^{p^{*}}(\\mathbb R^{n})}+\\left\\Vert {\ ext {Curl}}P\\right\\Vert _{{\ ext {L}}^{p}(\\mathbb R^{n})} \\Big ) \\end{aligned}$$\\end{document}holds for all compactly supported Pin {text {C}}_{c}^{infty }(mathbb R^{n};mathbb R^{ntimes n}), where {text {Curl}}P displays the matrix curl. Being applicable to incompatible, that is, non-gradient matrix fields as well, such inequalities generalise the usual Korn-type inequalities used e.g. in linear elasticity. Different from previous contributions, the results gathered in this paper are applicable to all dimensions and optimal. This particularly necessitates the distinction of different combinations between the ellipticities of {mathscr {A}}, the integrability p and the underlying space dimensions n, especially requiring a finer analysis in the two-dimensional situation.

Bronzing effect: predicting the color shine of printed surfaces by estimating the refractive index of the inks.

This paper investigates the optical phenomenon responsible for the colored shine that sometimes appears at the surface of ink layers in the specular direction, often called "bronzing" or "gloss differential." The prediction of this shine effect relies on the Fresnel formulas of the air/ink interface. The complex refractive index of the ink must therefore be determined, which is made difficult because of the roughness of inked printing supports. We propose a generic method that can be applied to any ink, without any prior knowledge of its composition or the printing substrate. In order to reduce light scattering, a solid colored area is printed with the studied ink on a glossy paper previously printed with black ink. By ellipsometry, we determine the effective refractive index of the sample. The intrinsic complex refractive index of the ink can then be extracted by modeling the optical response of the inked surface with a set of Gaussian oscillators, among which one of them approaches residual scattering. With this data, we could proceed to a fine colorimetric analysis of the bronzing color of some cyan, magenta, and yellow inks. In particular, we show that this gloss color is slightly shifted from the complementary of the ink's usual color in diffuse reflection.

Phase-field model of bilipid membrane electroporation.

This paper proposes a new model of membrane electropermeabilisation that combines the water content of the membrane and the transmembrane voltage. Interestingly, thanks to a well defined free-energy of the membrane, we somehow generalise the seminal approach of Chizmadzhev, Weaver and Krassowska, getting rid of the geometrical cylindrical assumption upon which most of the current electroporation models are based. Our approach is physically relevant and we recover a surface diffusion equation of the lipid phase proposed by Leguèbe et al. in a previous phenomenological model. We also perform a fine analysis of the involved nonlocal operators in two simple configurations (a spherical membrane and a flat periodic membrane) that enables us to compare the time constants of the phenomenon in spherical and flat membranes. An accurate splitting scheme combined with Fast Fourier Transforms is developed for efficient computations of the model. Our numerical results enable us to make a link between the molecular dynamics simulations of membrane permeabilisation and the experimental observations on vesicles and cells.

Quantitative particle approximation of nonlinear Fokker-Planck equations with singular kernel

In this work, we obtain quantitative convergence of moderately interacting particle systems towards solutions of nonlinear Fokker-Planck equations with singular kernels. In addition, we prove the well-posedness for the McKean-Vlasov SDEs involving these singular kernels and the trajectorial propagation of chaos for the associated moderately interacting particle systems. Our results only require very weak regularity on the interaction kernel, including the Biot-Savart kernel, and attractive kernels such as Riesz and Keller-Segel kernels in arbitrary dimension. This seems to be the first time that such quantitative convergence results are obtained in Lebesgue and Sobolev norms for the aforementioned kernels. In particular, this convergence still holds (locally in time) for PDEs exhibiting a blow-up in finite time. The proofs are based on a semigroup approach combined with a fine analysis of the Sobolev regularity of infinite-dimensional stochastic convolution integrals, and we also exploit the regularity of the solutions of the limiting equation.

A Blaschke–Lebesgue theorem for the Cheeger constant

In this paper, we prove a new extremal property of the Reuleaux triangle: it maximizes the Cheeger constant among all bodies of (same) constant width. The proof relies on a fine analysis of the optimality conditions satisfied by an optimal Reuleaux polygon together with an explicit upper bound for the inradius of the optimal domain. As a possible perspective, we conjecture that this maximal property of the Reuleaux triangle holds for the first eigenvalue of the [Formula: see text]-Laplacian for any [Formula: see text] (this paper covers the case [Formula: see text] whereas the case [Formula: see text] was already known).