Triple Correlation Research Articles

On the Construction of Turbulent Transfer Spectral Models Using 3D Numerical Simulation of Taylor–Green Vortex Decay

In the present paper we recall the classical Taylor–Green vortex turbulent decay in terms of isotropic turbulence theory. In particular, we calculate the spectral turbulent kinetic energy transfer $$T(k)$$ and the spectral flux $${{\Pi }_{E}}(k)$$ basing on the longitudinal triple correlation function (the two-point third-order velocity moment). These functions can be also obtained in other way via the generalized Karman–Howarth equation for homogeneous turbulence using integral of triple modes interaction. In both cases, the spectral transfer and the flux appear to be different from the characteristics of isotropic or homogeneous turbulence due to the peculiarities of the problem statement. The results obtained outline the range of obstacles associated with the construction of spectral turbulent models in complex heat and mass transfer problems arising due to periodicity effects, closeness of integral turbulent scales to modeling box size and lack of spectral resolution.

A computational model for controlling conformational cooperativity and function in proteins.

We present a computational model that allows for rapid prediction of correlations among a set of residue pairs when the fluctuations of another set of residues are perturbed. The simple theory presented here is based on the knowledge of the fluctuation covariance matrix only. In this sense, the theory is model independent and therefore universal. Perturbation of any set of fluctuations and the resulting response of the remaining set are calculated using conditional probabilities of a multivariate normal distribution. The model is expected to rapidly and accurately map the consequences of mutations in proteins, as well as allosteric activity and ligand binding. Knowledge of triple correlations of fluctuations of residues i, j, and k, emerges as the necessary source of information for controlling residue pairs by perturbing a distant residue. Triple correlations have not received wide attention in literature. Perturbation-response-function relations for ubiquitin (UBQ) are discussed as an example. Covariance matrix for UBQ obtained from the Gaussian Network Model combined with the present computational algorithm is able to reflect the millisecond molecular dynamics correlations and observed NMR results. © 2018 Wiley Periodicals, Inc.

Exact result for mixed triple two-point correlations of velocity and velocity gradients in isotropic turbulence

ABSTRACTOn the grounds of Kolmogorov's 4/5 law analytical relations for triple two-point correlations of velocity and velocity gradients in homogeneous isotropic incompressible turbulence are derived. The corresponding correlation tensor can be expressed in terms of dissipation ε, the second-order longitudinal velocity structure function and one more scalar function of distance between the points. However, some components of the tensor do not depend on . The derived analytical results are in agreement with the data obtained from direct numerical simulations. The function can be well approximated in the inertial range by a constant value that depends on the dissipation ε only. The application of the obtained correlators in the turbulent transport theory is discussed.

Intensities of ancient earthquakes, earthquake magnitude and soil dynamics effects. Evidence from the 1750 Croatia earthquake

A problem in the study of pre-instrumental earthquakes is how to reconstruct their parameters based on usually fragmentary evidence of seismic intensities, which reflect the combined effect of fault dynamics, of radiation of seismic waves, and of local amplification or attenuation of strong seismic motions. This problem is highlighted in the 1750 earthquake in Croatia, in the active compressional margin of NW Adriatic, an area with rarely known seismic history. Recent high-quality historical and archaeological data revealed that the 1750 earthquake was associated with high (up to VIII) seismic intensities, which were assigned to local amplification of strong motion generated by a magnitude 5 earthquake. This scenario points to a nearly aseismic plate boundary and to an unusually long meizoseismal zone for a small earthquake. On the contrary, in this study, the 1750 earthquake is associated with a segment of a major thrust and with a M > 6.0 earthquake which produced moderate accelerations. These results were based on a triple correlation between (1) a Finite Fault Model derived from elastic dislocation analysis of differential subsidence of submerged coastal notches, (2) a major composite thrust and (3) the distribution of areas of high seismic intensities. This result provides some input for the estimation of the seismic hazard/risk in the study area, indicates that the Adria-Eurasia collision front in NW Croatia is not essentially aseismic, and highlights the need to include soil dynamics effects in the study of palaeoseismic events.

Triple resonance EPR spectroscopy determines the Mn2+ coordination to ATP

Mn2+ often serves as a paramagnetic substitute to Mg2+, providing means for exploring the close environment of Mg2+ in many biological systems where it serves as an essential co-factor. This applies to proteins with ATPase activity, where the ATP hydrolysis requires the binding of Mg2+-ATP to the ATPase active site. In this context, it is important to distinguish between the Mn2+ coordination mode with free ATP in solution as compared to the protein bound case. In this work, we explore the Mn2+ complexes with ATP, the non-hydrolysable ATP analog, AMPPNP, and ADP free in solution. Using W-band 31P electron-nuclear double resonance (ENDOR) we obtained information about the coordination to the phosphates, whereas from electron-electron double resonance (ELDOR) – detected NMR (EDNMR) we determined the coordination to an adenosine nitrogen. The coordination to these ligands has been reported earlier, but whether the nitrogen and phosphate coordination is within the same nucleotide molecules or different ones is still under debate. By applying the correlation technique, THYCOS (triple hyperfine correlation spectroscopy), and measuring 15N-31P correlations we establish that in Mn-ATP in solution both phosphates and a nitrogen are coordinated to the Mn2+ ion. We also carried out DFT calculations to substantiate this finding. In addition, we expanded the understanding of the THYCOS experiment by comparing it to 2D-EDNMR for 55Mn-31P correlation experiments and through simulations of THYCOS and 2D-EDNMR spectra with 15N-31P correlations.

Calculation of Higher-Order Moments in the Atmospheric Boundary Layer

The results of analyzing a number of models to calculate the statistical fourth-order moments of turbulent fluctuations of vertical velocity and temperature, which describe diffusion processes in equations for triple correlations in RANS models, are presented. Correct calculation of higher-order moments allows adequate description of the impact of large-scale vortex structures on the vertical flow of turbulence energy, as well as the impact of chemical reactions (in the case of reactive impurities) and/or phase transitions (moisture condensation and evaporation) in the atmospheric boundary layer.Results of calculations with the use of the quasi-normality hypothesis, a number of empirical formulas. and algebraic models for fourth-order cumulants are comparedwith in situ measurements in the convective boundary layer of the atmosphere. It is shown that the secondorder- closure models, which are much more efficient in numerical implementation than the thirdorder models, predict the behavior of the higher-order moments not worse than the latter.

Reconstruction of Feedback Polynomial of Synchronous Scrambler Based on Triple Correlation Characteristics of M-Sequences

Reconstruction of Feedback Polynomial of Synchronous Scrambler Based on Triple Correlation Characteristics of M-Sequences

Prognostic value of androgen receptor and FOXA1 co-expression in non-metastatic triple negative breast cancer and correlation with other biomarkers

BackgroundIn luminal androgen receptor (AR) tumours, FOXA1 may direct AR to sites occupied by ER in luminal tumours, thus stimulating proliferation.MethodsAR and FOXA1 expression were evaluated by immunohistochemistry in 333 non-metastatic triple-negative breast cancers (TNBC). Positivity threshold was set at ≥ 1% staining. Lymphocytic infiltration, PD-L1expression, PIK3CA mutations, PTEN defects and BRCA1 promoter methylation were assessed.ResultsAR + /FOXA1 + tumours (42.4%) were more frequently: found in older patients, lobular, of lower nuclear grade, with more frequently PIK3CA mutations; exhibited less frequently BRCA1 promoter methylation, defects of PTEN and PD-L1 expression than others. Recurrence-free and overall survivals were significantly lower for AR + /FOXA1 + TNBC (median follow-up: 7.8 years).ConclusionsAR + /FOXA1 + expression defines a luminal-like TNBC subgroup affected with a worse outcome compared to other TNBC and a higher risk of late recurrences. This subgroup appears enriched in PIK3CA mutations, suggesting a role for PI3K inhibitors in this subgroup.

Turbulence closure models for free electroconvection

Electroconvection has been simulated in a number of recent studies, given its application in heat transfer enhancement, electrostatic atomizers and flow control. In practical applications, such as in charge injection atomizers, the electric Reynolds number can be sufficiently high such that the well-described ordered large scale electrohydrodynamic (EHD) instabilities that normally appear in electroconvection can dissipate and form into a wider distribution of length-scales. This purely electrohydrodynamically driven chaotic flow has features that resemble turbulent natural convection, and can dominate the operational regime of practical devices. Despite its practical relevance, Reynolds averaged turbulence model closures for EHD are unavailable, which currently makes direct numerical simulation the main viable option for EHD flows. Closure of EHD turbulence in free electro-convection is examined here through implementation of Reynolds stress model (RSM) closures using EHD specific timescales for the unclosed terms appearing in the turbulent scalar flux and space-charge scalar variance equations. A new closure for the highly non-linear triple correlation (q′E′u′¯), a term which is specific to EHD, is also presented. The work demonstrates that Reynolds stress closures are a feasible modeling route for EHD flows, with errors approaching similar values as in thermal Rayleigh–Benard convection at analogous levels of turbulence.

The γ-ray spectroscopy studies of low-spin structures in 210Bi and 206Tl using cold neutron capture reactions

The γ-coincidence studies of low-spin structures of 210Bi and 206Tl are presented. The 210Bi nucleus, populated in thermal neutron capture reaction, was investigated using EXILL HPGe array at Institut Laue-Langevin in Grenoble. The experimental results were compared to the shell-model calculations allowing to draw the conclusions on the nature of the low-spin excitations populated below the neutron binding energy in 210Bi (4.6 MeV). It has been found that some levels cannot be described by the valence proton and neutron couplings, but may arise from couplings of valence particles to the 3- octupole phonon of the doubly magic 208Pb core. Moreover, preliminary results of a low-spin structure measurements of 206Tl by the γ-coincidence technique, making use of the 205Tl(n,γ)206Tl reaction at the FIPPS prompt γ-ray spectroscopy facility of ILL are shown. The population of a large number of excited states of 206Tl above the ground state up to the neutron binding energy (at 6.5 MeV), within a few units of spin is expected. The analysis involving double and triple γ-coincidences and γγ-angular correlations will allow to significantly extend the experimental information on the energy and spin-parity of the levels in 206Tl. This will help shedding light on the proton-hole and neutron-hole couplings near the doubly magic core 208Pb.

Efficacy Study of Metronomic Chemotherapy in Metastatic Triple Negative Breast Cancer and Correlation with VEGF, TSP Levels

Background: Treatment refractory metastatic breast cancer patients are at best treated palliatively. We evaluated the effects of metronomic chemotherapy on survival outcomes in this population. Methods: Twenty eight subjects with treatment refractory (n = 21) and treatment naive (n = 7) MBC were included in an open label single arm efficacy study of metronomic chemotherapy. Patients were given a chemotherapy regimen of Tab. Cyclophosphamide 50 mg once daily and Tab. Methotrexate 2.5 mg twice in a week over a minimum period of 3 months or until the progression of their disease whichever was earlier. Monitoring of serum VEGF and Thrombospondin levels were done to correlate the response rates. Data were analysed using chi square test for proportions and Kaplan Meir Survival analysis. Results: The mean age of the study population was 51.5 ± 14.2 years. The mean duration of metronomic chemotherapy was 123.89 ± 97.6 days. Overall 71.4% had progressive disease and 28.6% had stable disease. 55.6% with treatment naive metastatic breast cancer had stable disease compared to 15.8% of treatment refractory metastatic breast cancer. There was also a significant improvement in progression free survival in those with tumor load less than 5 cms compared to >5 cms and in grade 2 compared to grade 3 disease. There was no correlation of serum VEGF levels before and after chemotherapy. There is no significant decrease in TSP levels. Conclusion: The results suggest stable response in one third of study patients. Performance status and tumor load are important predictors in this category of population. There is no significant correlation of serum VEGF and TSP levels before and after chemotherapy. Also, there was no significant correlation of biomarker levels in responding and non-responding patients.

A Triple Correlation Study - Fine Needle Aspiration Cytology and Imprint Cytology of Lymph node with Histopathological Examination

A Triple Correlation Study - Fine Needle Aspiration Cytology and Imprint Cytology of Lymph node with Histopathological Examination

Long non-coding RNA-adriamycin resistance-associated is overexpressed in triple negative breast cancer and contributes to shorter survival

Objective To explore the expression of long non-coding RNA (lncRNA)-adriamycin resistance-associated (ARA) in tissue samples of triple negative breast cancer (TNBC) patients and correlation to the clinical and pathological characteristics, and survival in TNBC. Methods Using real-time quantitative polymerase chain reaction (Real-time PCR) to test the lncRNA-ARA levels in TNBC (n=55), Luminal (n=20) and human epidermalgrowth factor receptor-2 (Her-2) (n=20) subtypes, and adjacent tissues in TNBC. The correlation between lncRNA-ARA and the clinicopathological characteristics in TNBC were analyzed. Kaplan-Meier analysis was utilized to evaluate the effect of ARA on TNBC disease-free survival. Results The lncRNA-ARA level was higher in TNBC samples than that in the other two breast cancer subtypes (TNBC: 10.35±2.29 vs. Luminal: 2.14±0.71 vs. Her-2: 3.32±0.90, P=0.000), also higher to adjacent tissues in TNBC (10.35±2.29 vs. 2.21±0.71, P=0.000). LncRNA-ARA was correlated to the tumor size and proliferation cell nuclear antigen (Ki-67) positively (P=0.034, 0.016). DFS rate of TNBC patient with higher level of lncRNA-ARA was shorter than that of that with lower ARA expression (37.6% vs. 67.2%, P=0.013). Conclusion LncRNA-ARA was over-expressed in TNBC samples, and related to tumor size and proliferation index. LncRNA-ARA is not a good prognostic factor in TNBC. Key words: Long non-coding RNA-adriamycin resistance-associated; Triple negative breast cancer; Survival

On triple correlations of Fourier coefficients of cusp forms

Assume that α,β are arbitrary arithmetic functions, and that γ is an arithmetic function, which does not correlate with additive characters. By introducing a simple argument, we are able to give a general upper bound for the triple correlation∑n∈(X,2X]α(n)β(n−h)γ(n+h) averaging over a short variable h. More precise estimates can be obtained by taking γ to be Fourier coefficients of cusp forms, which improve and streamline the results of Lin and Singh.

Experimental study on relation between scour and complex 3D flow field

In this paper scour and flow fields around two spur dikes with different submergence ratios located in a 90° developed bend were experimentally investigated. The spur dike and the scour rate around the low submerged spur dike is higher than that around the high submerged condition. The ejection and sweep events are the predominant events in the upstream region of the spur dike. The larger peak of the power spectrum and the higher frequencies of sweep and ejection events in low submerged condition increase the scour rate at the early stages of the scour process. Interaction events are the main events in the downstream recirculation zone and may be the principle reasons for the sediment deposition process. The scour initiation region cannot be predicted using variance of the vertical velocity component. However, the estimation of the bed shear stress using the Reynolds stresses can predict the scour initiation region correctly. Strong relationships between the scour rate and triple correlations, quadrant analysis, turbulent kinetic energy flux and power spectrum were found based on the fact that the scour rate increases in the low submergence condition by the latter parameters increments.

Algorithm for Reconstruction of 3D Images of Nanorice Particles from Diffraction Patterns of Two Particles in Independent Random Orientations with an X-ray Laser

The method of angular correlations recovers quantities from diffraction patterns of randomly oriented particles, as expected to be measured with an X-ray free electron laser (XFEL), proportional to quadratic functions of the spherical harmonic expansion coefficients of the diffraction volume of a single particle. We have previously shown that it is possible to reconstruct a randomly oriented icosahedral or helical virus from the average over all measured diffraction patterns of such correlations. We point out in this paper that a structure of even simpler particles of 50 Å or so in diameter and consisting of heavier atomic elements (to enhance scattering) that has been used as a test case for reconstructions from XFEL diffraction patterns can also be solved by this technique. Even though there has been earlier work on similar objects (prolate spheroids), one advantage of the present technique is its potential to also work with diffraction patterns not only due to single particles as has been suggested on the basis on nonoverlapping delta functions of angular scattering. Accordingly, we calculated from the diffraction patterns the angular momentum expansions of the pair correlations and triple correlations for general particle images and reconstructed those images in the standard way. Although the images looked pretty much the same, it is not totally clear to us that the angular correlations are exactly the same as different numbers of particles due to the possibility of constructive or destructive interference between the scattered waves from different particles. It is of course known that, for a large number of particles contributing to a diffraction parttern, the correlations converge to that of a single particle. It could be that the lack of perfect agreement between the images reconstructed with one and two particles is due to uncancelling constructive and destructive conditions that are not found in the case of solution scattering.

Thermophysical properties of krypton-helium gas mixtures from ab initio pair potentials.

A new potential energy curve for the krypton-helium atom pair was developed using supermolecular ab initio computations for 34 interatomic distances. Values for the interaction energies at the complete basis set limit were obtained from calculations with the coupled-cluster method with single, double, and perturbative triple excitations and correlation consistent basis sets up to sextuple-zeta quality augmented with mid-bond functions. Higher-order coupled-cluster excitations up to the full quadruple level were accounted for in a scheme of successive correction terms. Core-core and core-valence correlation effects were included. Relativistic corrections were considered not only at the scalar relativistic level but also using full four-component Dirac-Coulomb and Dirac-Coulomb-Gaunt calculations. The fitted analytical pair potential function is characterized by a well depth of 31.42 K with an estimated standard uncertainty of 0.08 K. Statistical thermodynamics was applied to compute the krypton-helium cross second virial coefficients. The results show a very good agreement with the best experimental data. Kinetic theory calculations based on classical and quantum-mechanical approaches for the underlying collision dynamics were utilized to compute the transport properties of krypton-helium mixtures in the dilute-gas limit for a large temperature range. The results were analyzed with respect to the orders of approximation of kinetic theory and compared with experimental data. Especially the data for the binary diffusion coefficient confirm the predictive quality of the new potential. Furthermore, inconsistencies between two empirical pair potential functions for the krypton-helium system from the literature could be resolved.

Statistical analysis using the multiple regression research in areas of the indefinite chilled cast–iron rolls manufacturing

To analyze the metallurgical processes is used, mainly, the statistical fundamental methods that permit to draw conclusions, from the observed values, about the repartition of the frequencies of various parameters, about their interaction, about verification validity of certain premises, and about the research of the dependencies among different parameters. In this sense, the realization of optimum chemical compositions of the cast–iron can constitute a technical efficient way to assure the exploitation properties, the material from which the rolling mills rolls are manufactured having an important role in this sense. This paper reviews key aspects of roll material properties and presents an analysis of the influences of chemical composition upon the mechanical properties of the indefinite cast iron rolls. Now, using the multivariate research, we present some mathematical correlations and graphical interpretations between the hardness and the chemical composition. Using the double and triple correlations variation boundaries for the chemical composition, in view the obtaining the optimal values of the hardness of indefinite cast iron rolls, are obtained. The partial results and evidence obtained by actual experiments are presented. For the multiple regression equations, correlation coefficients and graphical representations the software MATLAB was used.

A new measurement of electron transverse polarization in polarized nuclear β-decay

The Mott polarimetry for T-violation (MTV) experiment tests time-reversal symmetry in polarized nuclear [Formula: see text]-decay by measuring an electron’s transverse polarization as a form of angular asymmetry in Mott scattering using a thin metal foil. A Mott scattering analyzer system developed using a tracking detector to measure scattering angles offers better event selectivity than conventional counter experiments. In this paper, we describe a pilot experiment conducted at KEK-TRIAC using a prototype system with a polarized 8Li beam. The experiment confirmed the sound performance of our Mott analyzer system to measure T-violating triple correlation (R correlation), and therefore recommends its use in higher-precision experiments at the TRIUMF-ISAC.

A Measurement of Radius Inflation in the Pleiades and Its Relation to Rotation and Lithium Depletion

Abstract Precise measurements of eclipsing binary parameters and statistical studies of young clusters have suggested that some magnetically active low-mass dwarfs possess radii inflated by ∼5%–15% relative to theoretical expectations. If true, this effect should be pronounced in young open clusters, due to the rapid rotation and strong magnetic activity of their most extreme members. We explore this possibility by determining empirical radii for 83 members of the nearby Pleiades open cluster, using spectral energy distribution fitting to establish with a typical accuracy of ≈3% together with color and spectro-photometric indices to determine . We find several Pleiades members with radii inflated above radius- models from state-of-the-art calculations, and apparent dispersions in radii for the K-dwarfs of the cluster. Moreover, we demonstrate that this putative radius inflation correlates strongly with rotation rate, consistent with inflation of young stars by magnetic activity and/or starspots. We argue that this signal is not a consequence of starspot-induced color anomalies, binarity, or depth effects in the cluster, employing Gaia DR1 distances as a check. Finally, we consider the lithium abundances of these stars, demonstrating a triple correlation between rotation rate, radius inflation, and enhanced lithium abundance. Our result—already significant to ∼99.99% confidence—provides strong support for a magnetic origin of the inflated radii and lithium dispersion observed in young, low-mass stars.