Probable Orientation Research Articles

Complex polymer orientation

Previously, we explored the dynamics of a dilute suspension of rigid dumbbells as a model for polymeric liquids in large-amplitude oscillatory shear (LAOS) flow. We derived the expression for the polymer orientation distribution, and then we decomposed this function into its first five harmonics (the zeroth, first, second, third and fourth harmonics). In this work, we separate each harmonic into its components in-phase and out-of-phase with cosnωt, and then use three-dimensional imaging to investigate complex polymer motion in LAOS. Our analysis focuses on the nonlinear viscoelastic regime, specifically, where both λω and λγ˙0 are unity. We learn that harmonic components, in-phase and out-of-phase with cosnωt, contribute to orientation differently, and that out-of-phase components tend to give more probable orientation away from the flow direction. We also find that some orientation contributions are caused by interferences between complex components, some constructive and some destructive.

First-order theory for Earth’s inner-core anisotropy due to super-rotation and Ramachandran interaction

Solidification mechanism at the Lehmann (inner core) boundary are postulated on the basis of Ramachandran interaction by taking the fluctuating inner core super-rotation into account. The postulates are found to be consistent with compressional or P-wave velocity obtained from seismic data analysis. We justify these postulates to be physically sound and precise, and show that the fluctuating inner core super-rotation causes significant changes to the strength of Fe–Fe Ramachandran interaction, which then leads to the observed asymmetric and anisotropic inner core. Our postulates also reliably explain that the depth-dependent anisotropic P-wave attenuation close to inner core surface (to about 100 km deep) is due to phonon excitation probability and different atomic orientation. We also discuss the consistency of our postulates with respect to asymmetric inner core anisotropy (between western and eastern inner core hemispheres).

Cordycepin an Adenosine Analogue Executes Anti Rotaviral Effect by Stimulating Induction of Type I Interferon

Abstract Objectives: Rotavirus is the single most common etiological pathogen of severe diarrhea in infants causing death of over half a million infants a year. In spite of such a huge disease burden, still no effective antivirals are available against rotavirus. Cordycepin (3’-deoxyadenosine), an adenosine analogue, has been reported to modulate cell proliferation, platelet aggregation and provide protection against HIV infection. Herein, attempts were made to analyze efficacy of cordycepin for protection against rotavirus and underlying mechanism. Methods Cordycepin’s anti-rotaviral activity was elucidated against simian rotavirus strain SA11 (H96), rhesus strain RRV, human strain Wa (in vitro) and murine strain EW (in BALB/c). Plaque assay, qPCR for viral transcripts and immunoblotting of viral proteins were done to examine viral abundance. Effect of cordycepin on Interferon pathway was analyzed by immunoblotting, co-immunoprecipitation and molecular docking. Results Cordycepin was found to reduce propagation of different rotavirus strains such as SA11, RRV, Wa at 64μM with minimal cytotoxicity in vitro and EW in BALB/c mice. Protection was obtained upto 24 hours, after virus infection at both low and high multiplicity of infection. Sensitivity of rotavirus infection to Interferons has been documented. In cordycepin treated cells increased induction of Interferon and downstream antiviral proteins were observed. Cordycepin treatment leads to RIGI-MAVS interaction, IRF3 activation, and Interferon induction. By using different software probable docking sites and orientation of cordycepin and RIG-I were predicted. Cordycepin was found to have relatively higher binding probability for ATP binding domain than other domains. In Vero cells,deficient in Interferon signalling, cordycepin failed to protect against rotavirus. This suggests that though cordycepin may have other effects but anti-rotaviral effects were due to boosting of cellular innate immune responses mediated by Interferon. Conclusions Overall this study highlights that cordycepin exerts its anti-rotaviral activity by modulating immune signalling through enhanced Interferon production.

Theoretical Study of Copper (II) Oxide Clusters and their Interaction with CO

Copper (II) oxide clusters (CuO)nwith n = 1 – 4, 6 have been calculated by DFT method with the exchange-correlation functional B3LYP. The structural, energy and electronic properties have been studied. Much attention was given to the interaction between CO and active centers of the clusters. The most probable orientation of CO on the metal oxide surface has been determined and the stability of clusters has been evaluated.

Birth weight and two possible types of maternal effects on male sexual orientation: A clinical study of children and adolescents referred to a Gender Identity Service

This study tested predictions regarding two hypothesized maternal immune responses influencing sexual orientation: one affecting homosexual males with high fraternal birth order and another affecting firstborn homosexual individuals whose mothers experience repeated miscarriage after the birth of the first child. Low birth weight was treated as a marker of possible exposure to a maternal immune response during gestation. Birth weight was examined relative to sibship characteristics in a clinical sample of youth (N = 1,722) classified as heterosexual or homosexual based on self-reported or probable sexual orientation. No female sexual orientation differences in birth weight were found. Homosexual, compared to heterosexual, males showed lower birth weight if they had one or more older brothers--and especially two or more older brothers--or if they were an only-child. These findings support the existence of two maternal immune responses influencing male sexual orientation and possibly also cross-gender behavior and identity.

Adsorption of hydrophobin on different self-assembled monolayers: the role of the hydrophobic dipole and the electric dipole.

In this work, the adsorptions of hydrophobin (HFBI) on four different self-assembled monolayers (SAMs) (i.e., CH3-SAM, OH-SAM, COOH-SAM, and NH2-SAM) were investigated by parallel tempering Monte Carlo and molecular dynamics simulations. Simulation results indicate that the orientation of HFBI adsorbed on neutral surfaces is dominated by a hydrophobic dipole. HFBI adsorbs on the hydrophobic CH3-SAM through its hydrophobic patch and adopts a nearly vertical hydrophobic dipole relative to the surface, while it is nearly horizontal when adsorbed on the hydrophilic OH-SAM. For charged SAM surfaces, HFBI adopts a nearly vertical electric dipole relative to the surface. HFBI has the narrowest orientation distribution on the CH3-SAM, and thus can form an ordered monolayer and reverse the wettability of the surface. For HFBI adsorption on charged SAMs, the adsorption strength weakens as the surface charge density increases. Compared with those on other SAMs, a larger area of the hydrophobic patch is exposed to the solution when HFBI adsorbs on the NH2-SAM. This leads to an increase of the hydrophobicity of the surface, which is consistent with the experimental results. The binding of HFBI to the CH3-SAM is mainly through hydrophobic interactions, while it is mediated through a hydration water layer near the surface for the OH-SAM. For the charged SAM surfaces, the adsorption is mainly induced by electrostatic interactions between the charged surfaces and the oppositely charged residues. The effect of a hydrophobic dipole on protein adsorption onto hydrophobic surfaces is similar to that of an electric dipole for charged surfaces. Therefore, the hydrophobic dipole may be applied to predict the probable orientations of protein adsorbed on hydrophobic surfaces.

Explicit spectral response of an intramolecular charge transfer molecule within microheterogeneous micellar environments

Photophysical properties of a potent intramolecular charge transfer probe viz., 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid methyl ester (DPDAME) have been investigated in aqueous micellar environments using spectroscopic techniques. The intramolecular charge transfer (ICT) fluorescence of DPDAME is found to display remarkable hypsochromic shift coupled with intensity enhancement within the microheterogeneous micellar environments. This is also associated with discernible increase in fluorescence anisotropy whereby indicating the impartation of considerable motional restrictions on the fluorophore within the micellar systems. The fluorescence anisotropy results are also processed to delve into an estimate of the microviscosity of the probe environment at the binding site on the micellar aggregates. Quantitative evaluation of the probe–micelle binding strength has been achieved from fluorescence data in terms of binding constant and free energy change of the interaction process. The extensive polarity-sensitive fluorescence behavior of DPDAME has been exploited to cast light on assessing the micropolarity at the interaction site of the probe within the micelles. This information has in turn been efficiently employed as the actuating avenue to argue on complex issues like probable location, distribution and orientation of the probe within the micellar aggregates. The pattern of variation of emission intensity of DPDAME as a function of surfactant concentrations is found to reveal the existence of multiple critical micellar concentration (CMC). Overall, the present results have been argued to reflect the commendable efficiency of DPDAME to function as a prospective molecular reporter for complex microheterogeneous micellar environments.

Nuclear Versus Side-Chain Bromination of 4-Methoxy Toluene by an Electrochemical Method

The electrochemical bromination of 4-methoxy toluene by two-phase electrolysis yields 3-bromo 4-methoxy toluene at first, which subsequently undergoes side-chain bromination to give 3-bromo 4-methoxy benzyl bromide as a final product in 86% yield. The two-phase electrolysis consists of 25–50% NaBr as aqueous electrolyte and CHCl3 containing aromatic compound as organic phase. The reaction temperature is maintained at 10–25 °C. The probable orientation of bromine atom in an alkyl aromatic compound (nuclear versus side chain) is explained from the experimental result.

A Drop Test for Finding the most Probable Resting Orientation of a Part

The material handling is the art of moving, orienting, packing and storing the part. Industrial feeders are used to facilitate the operations by feeding the parts in a specific quantity and at a perfect orientation. It is a tedious task to obtain a particular part orientation, at the assembly station, in a short lead time. To overcome this problem, part feeders are used to segregate and orient parts prior to packing. The natural resting orientation of the part is the orientation in which the part rests on a horizontal hard surface, when dropped from a height. The most probable natural resting orientation of the part has to be identified which helps in the effective design of feeder and orienting devices. In this paper, an attempt was made to study the effect of initial orientation from different heights on natural resting orientation. Drop test was conducted at different heights with each initial orientation. The favorable orientation of the part (or) the most probable natural resting orientation is identified using drop test. In this work, most probable natural resting orientation of a typical asymmetric component, brake pad, is identified.

Mg-Gd-Zn合金の板状析出物の構造と方位解析

Precipitates in a Mg-2Gd-1Zn (at%) alloy, aged at 573 K for 100 h after forging, have been characterized using transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD). TEM observation reveals that the precipitates have thin plate morphology. The energy dispersive X-ray spectrometry (EDX) and selected area electron diffraction (SAED) pattern have indicated that the plate-shaped precipitate has an fcc structure and a lattice parameter of approximately 2.23 nm, which is identical to β-Mg5Gd. It is suggested that the most probable dominant orientation relationship between the β-Mg5Gd precipitate and α-Mg matrix is (1120)α // (001)β and [0001]α // [110]β based on the crystal orientation analysis using EBSD. It is speculated that the strengthening in the Mg-Gd-Zn alloy is attributable to the plate-shaped β-Mg5Gd precipitates. The precipitates which are formed on prismatic planes of α-Mg matrix during the heat treatment can provide the most effective obstacles to basal dislocation slip.

Calibrating a wide-area camera network with non-overlapping views using mobile devices

In a wide-area camera network, cameras are often placed such that their views do not overlap. Collaborative tasks such as tracking and activity analysis still require discovering the network topology including the extrinsic calibration of the cameras. This work addresses the problem of calibrating a fixed camera in a wide-area camera network in a global coordinate system so that the results can be shared across calibrations. We achieve this by using commonly available mobile devices such as smartphones. At least one mobile device takes images that overlap with a fixed camera's view and records the GPS position and 3D orientation of the device when an image is captured. These sensor measurements (including the image, GPS position, and device orientation) are fused in order to calibrate the fixed camera. This article derives a novel maximum likelihood estimation formulation for finding the most probable location and orientation of a fixed camera. This formulation is solved in a distributed manner using a consensus algorithm. We evaluate the efficacy of the proposed methodology with several simulated and real-world datasets.

Probability density distribution of the orientation of strength-controlling flaws from multiaxial loading using the unit-sphere stochastic strength model for anisotropy

Models that predict the failure probability of monolithic glass and ceramic components under multiaxial loading have been developed by authors such as Batdorf, Evans, and Matsuo. These “unit-sphere” failure models assume that the strength-controlling flaws are randomly oriented, noninteracting planar microcracks of specified geometry but of variable size. The purpose of this paper is to describe a formulation of the probability density distribution of the orientation of critical strength-controlling flaws that results from an applied load. This distribution is a function of the multiaxial stress state, the shear sensitivity of the flaws, the Weibull modulus, and the strength anisotropy. Examples are provided showing the predicted response on the unit sphere for various stress states for isotropic and transversely isotropic (anisotropic) materials—including the most probable orientation of critical flaws for offset uniaxial loads with strength anisotropy. The author anticipates that this information could be used to determine anisotropic stiffness degradation or anisotropic damage evolution for individual brittle (or quasi-brittle) composite material constituents within finite element or micromechanics-based software.

Orbital orientation evolution of massive binary black holes at the centres of non-spherical galaxies

At the centre of a spherical and kinematically isotropic galaxy, the orientation of a massive binary black hole (BBH) orbit (i.e. the direction of the BBH orbital angular momentum) undergoes a random walk. If the stars in a spherical system have non-zero total angular momentum, the BBH orbital orientation evolves towards aligning with the total stellar angular momentum direction. In this article, we show that a triaxial galaxy has an alignment-erasing effect, i.e. the alignment of the BBH orientation towards the galaxy rotation axis can be decreased significantly or erased. We also show that in a non-rotating axisymmetric galaxy the BBH orbital orientation evolves towards the axisymmetric axis and precesses about it in a retrograde direction. Our results provide a step towards understanding the spin orientation of the final merged black hole (and hence the probable orientation of any jet produced) within its host galaxy and may help to constrain the recoil velocity of the merged black hole arising from gravitational wave radiation as well.

Accurate New Method for Molecular Orientation Quantification Using Polarized Raman Spectroscopy

The physical properties of polymers are strongly affected by their molecular orientation. In this paper, we demonstrate for the first time a new and improved Raman spectroscopy method to characterize this key parameter. In recent years, Raman spectroscopy has emerged as an indispensable tool for this purpose, but its widespread use is still largely restricted by the experimental complexity and the limitations imposed by the standard quantification procedure, referred in this article as the depol constant (DC) method. We have very recently proposed and established theoretically a simplified quantification approach that is based on the most probable orientation distribution (MPD method). Herein, we demonstrate its experimental validity and its wide applicability by studying a series of samples from three highly dissimilar polymers (HDPE, PET, and PS), and covering the full possible orientation range. We show that the new MPD method overcomes the experimental and theoretical difficulties faced with the curre...

Mueller matrix form for the case of molecular light scattering by atmospheric gases

The Mueller matrix is derived for molecular light scattering. The derivation is based on the knowledge of the independence of density and anisotropy fluctuations in gases under low pressures and averaging over equally probable orientations of molecules. A comparison with some published matrices is presented.

Hierarchical micro-adaptation of biological structures by mechanical stimuli

The objective of this work is to develop a remodeling model for biological matter coupling two different processes in a 3D framework: reorientation of the preferential direction of a given fibered structure and reorientation of the fibrils or filaments that make up such a structure. This work uses the microsphere-based approach to take into account the micro mechanics involved in biological fibered structures regarding both their passive behavior and the reorientation of their micro constituents. Moreover, the macro behavior of the material as a whole is obtained by means of homogenizing the underlying micro response. We associate the orientation space of the integration directions to the physical space of micro-fibrils. To approximate the directional distribution of the fibrils within each fiber bundle, a Bingham probability orientation density function is introduced into the Helmholtz energy function. With all these assumptions, the problem is studied from an energetic point of view, describing the dissipation inherent to remodeling processes, and the evolution equations for both reorientations (change in preferential direction of the network and change in shape of the fibril distribution) re obtained. The model is included in a finite element code which allows computing different geometries and boundary value problems. This results in a complete methodology for characterizing the reorientation evolution of different fibered biological structures, such as cells. Our results show remodeling of fibered structures in two different scales, presenting a qualitatively good agreement with experimental findings in cell mechanics. Hierarchical structures align in the direction of the maximum principal direction of the considered stimulus and narrow in the perpendicular direction. The dissipation rates follows predictable trends although there are no experimental findings to date for comparison. The incorporation of metabolic processes and an insight into cell-oriented mechano-sensing processes can help to overcome the limitations involved.

Fluorescence Quenching of 5,5′-Disulfopropyl-3,3′-dichlorothiacyanine Dye Adsorbed on Gold Nanoparticles

Nanoparticles (NPs) modified with fluorescent cyanine dyes can exhibit fluorescent quenching properties due to energy and/or electron transfer, and these systems have many applications in catalysis, drug delivery, nanoelectronics, medical diagnostics, and chemical sensing. The aim of this work was to investigate the adsorption of cyanine dye 5,5′-disulfopropyl-3,3′-dichlorothiacyanine (TC) on the surface of citrate capped gold nanoparticles (AuNPs) with the average core sizes of 9, 17, and 30 nm using various experimental techniques. The measurements of fluorescence corrected for inner filter effects (IFE) of the particle–dye assembly clearly indicated that the fluorescence of TC was quenched by AuNPs on the concentration dependent manner, and the equilibrium constants for the sorption of TC on the NP surface were calculated. Significant increase of fluorescence quenching was noticed when NP size increased, keeping the concentration of NPs of different size constant. By comparing experimental and calculated results for quenching of TC dye fluorescence, we assumed that the maximum quenching was restricted to full monolayer coverage of TC on the NP surface. The conclusion was drawn that the most probable orientation of TC dye molecules on the NP surface was slanted and that the dye approached NP surface with its positively charged thiazole ring.

Invariant properties and rotation transformations of the GPR scattering matrix

Abstract We analyze the properties of the scattering matrix associated with the incident and scattered electric fields used in GPR. The elements of the scattering matrix provide information produced by different polarizations of the incident wave field. Rotationally invariant quantities such as trace, determinant and Frobenius norm lead to images that combine the information contained in the four elements of the scattering matrix in a mathematically simple and sound manner. The invariant quantities remove the directional properties implicit in the dipolar field used in GPR allowing the application of standard processing techniques designed for scalar fields, such as those used in seismic data processing. We illustrate the non-directional properties of the invariants using a 3D simulation of the wavefield produced by a point scatterer. The estimation of the azimuth angle of elongated targets is also explored using rotation transformations that maximize alternatively the co-polarized or the cross-polarized responses. The angle estimation is essentially an unstable process, particularly if low amplitudes or noisy data are involved. We apply the Frobenius norm ‖S‖F as a criterion for selection of the best amplitudes to use for a more stable and significant angle estimation. The performance of our formulation was tested with synthetic data produced by a 3D model of an air-filled metal pipe buried in a homogeneous halfspace. The images resulting from the invariants show a clear diffraction hyperbola suitable for a scalar wavefield migration, while the azimuth of the pipe is neatly resolved for amplitudes selected with ‖S‖F ≥ 0.4. A field experiment conducted above an aqueduct pipe illustrates the proposed methods with real data. The images obtained from the invariants are better than those from the individual elements of the scattering matrix. The azimuth estimated using our formulation is in agreement with the probable orientation of the aqueduct. Finally, a field experiment above a buried air-filled barrel shows that combining the information in the way proposed in this work may lead to an improved image of the subsurface target, the cost to pay is the lost of directional information contained in the scattering matrix. In general, we claim that the methods proposed in this work can be useful to analyze the information acquired by multicomponent GPR surveys using standard scalar wavefield algorithms.

Calculation of magnetization curves and probability distribution for monoclinic and uniaxial systems

We present the application of a simple classical statistical mechanics-based model to selected monoclinic and hexagonal model systems. In this model, we treat the magnetization as a classical vector whose angular orientation is dictated by the laws of equilibrium classical statistical mechanics. We calculate for these anisotropic systems, the magnetization curves, energy landscapes and probability distribution for different sets of relevant parameters and magnetic fields of different strengths and directions. Our results demonstrate a correlation between the most probable orientation of the magnetization vector, the system's parameters, and the external magnetic field.

Simple Estimation of Förster Resonance Energy Transfer (FRET) Orientation Factor Distribution in Membranes

Because of its acute sensitivity to distance in the nanometer scale, Förster resonance energy transfer (FRET) has found a large variety of applications in many fields of chemistry, physics, and biology. One important issue regarding the correct usage of FRET is its dependence on the donor-acceptor relative orientation, expressed as the orientation factor κ2. Different donor/acceptor conformations can lead to κ2 values in the 0 ≤ κ2 ≤ 4 range. Because the characteristic distance for FRET, R0, is proportional to (κ2)1/6, uncertainties in the orientation factor are reflected in the quality of information that can be retrieved from a FRET experiment. In most cases, the average value of κ2 corresponding to the dynamic isotropic limit (<κ2> = 2/3) is used for computation of R0 and hence donor-acceptor distances and acceptor concentrations. However, this can lead to significant error in unfavorable cases. This issue is more critical in membrane systems, because of their intrinsically anisotropic nature and their reduced fluidity in comparison to most common solvents. Here, a simple numerical simulation method for estimation of the probability density function of κ2 for membrane-embedded donor and acceptor fluorophores in the dynamic regime is presented. In the simplest form, the proposed procedure uses as input the most probable orientations of the donor and acceptor transition dipoles, obtained by experimental (including linear dichroism) or theoretical (such as molecular dynamics simulation) techniques. Optionally, information about the widths of the donor and/or acceptor angular distributions may be incorporated. The methodology is illustrated for special limiting cases and common membrane FRET pairs.