Model Of Weak Interactions Research Articles

Modeling of an Er3+-Doped ZBLAN Fiber Laser With Ion Clustering Effect

In this study, we proposed a numerical model incorporating ion clustering effect for an Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -doped ZBLAN fiber laser. Our proposed model does not use weak-interaction (WI) energy transfer parameters, instead, it is based on two separate rate equations for isolated and clustered ions, respectively, using conventional ionic interaction parameters, unlike the previously proposed WI model. We verified the efficacy of our proposed model by comparing the numerically calculated output curves with the experimentally measured ones in a Fabry-Pérot laser setup based on two different lengths of commercially available Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -doped ZBLAN fiber. The proposed model can readily provide an accurate prediction of the laser output performance without using WI energy transfer parameters. In addition, with the numerical calculation of the model, the relative number of clustered ions in a commercial ZBLAN fiber was indirectly found to be ∼18.1%. Lastly, we compared the calculation results of our model with those with strong-interaction (SI) and WI model, which are commonly used for Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -doped ZBLAN fiber lasers.

An SU(3) Electroweak Unified Model Using Generalized Yang-Mills Theory

Generalized Yang-Mills theory has a covariant derivative which contains both vector and scalar gauge bosons. Based on this theory, we construct an SU(3) unified model of electromagnetic and weak interactions to simplify the Weinberg-Salam model. By using the Nambu-Jona-Lasinio mechanism, the symmetry breaking can be realized dynamically. The masses of W±, Z0 are obtained and interactions between various particles are the same as that of the Weinberg-Salam model. At the same time, sin2 θw =1/4 can be given.

A genetic interaction of NRXN2 with GABRE, SYT1 and CASK in migraine patients: a case-control study

BackgroundMigraine is a multifactorial disorder that is more frequent (two to four times) in women than in men. In recent years, our research group has focused on the role of neurotransmitter release and its regulation. Neurexin (NRXN2) is one of the components of the synaptic vesicle machinery, responsible for connecting intracellular fusion proteins and synaptic vesicles.Our aim was to continue exploring the role and interaction of proteins involved in the control and promotion of neurotransmission in migraine susceptibility.MethodsA case-control study was performed comprising 183 migraineurs (148 females and 35 males) and 265 migraine-free controls (202 females and 63 males). Tagging single nucleotide polymorphisms of NRXN2 were genotyped to assess the association between NRXN2 and migraine susceptibility. The χ2 test was used to compare allele frequencies in cases and controls and odds ratios were estimated with 95% confidence intervals. Haplotype frequencies were compared between groups. Gene-gene interactions were analysed using the Multifactor Dimensionality Reduction v2.0.ResultsWe found a statistically significant interaction model (p = 0.009) in the female group between the genotypes CG of rs477138 (NRXN2) and CT of rs1158605 (GABRE). This interaction was validated by logistic regression, showing a significant risk effect [OR = 4.78 (95%CI: 1.76–12.97)] after a Bonferroni correction. Our data also supports a statistically significant interaction model (p = 0.011) in the female group between the GG of rs477138 in NRXN2 and, the rs2244325's GG genotype and rs2998250’s CC genotype of CASK. This interaction was also validated by logistic regression, with a protective effect [OR = 0.08 (95%CI: 0.01–0.75)]. A weak interaction model was found between NRXN2-SYT1. We have not found any statistically significant allelic or haplotypic associations between NRXN2 and migraine susceptibility.ConclusionsThis study unravels, for the first time, the gene-gene interactions between NRXN2, GABRE - a GABAA-receptor - and CASK, importantly it shows the synergetic effect between those genes and its relation with migraine susceptibility.These gene interactions, which may be a part of a larger network, can potentially help us in better understanding migraine aetiology and in development of new therapeutic approaches.

The Influence of Alumina Nanofibers on the Physical and Mechanical Properties of Mineral-Filled Polyethylene: an Experimental Study

Improvement of physical and mechanical characteristics of mineral-filled polyethylene (MFPE) upon addition of alumina nanofibers with a high aspect ratio has been experimental studied. It is shown that, at the weight concentration of alumina nanofibers of 0.1 wt %, the ultimate tensile strength increases from 3.82 ± 0.04 to 6.70 ± 0.07 MPa and the Young’s modulus increases from 1.08 ± 0.01 to 1.38 ± 0.01GPa (with respect to MFPE). The MFPE/Al2O3 nanofiber composite can be described within a model of weak adhesive interaction between a filler and a matrix with high friction.

Влияние нановолокон оксида алюминия на физико-механические свойства минералонаполненного полиэтилена: экспериментальное исследование

The paper presents the results of an experimental study of improving the physical and mechanical properties of mineral-filled polyethylene (MFPE) by adding high-aspect alumina nanofibers. It is shown that at a weight concentration of alumina nanofibers of 0.1 wt. %, the tensile strength increases from 3.82 ± 0.04 to 6.70 ± 0.07 MPa, and Young's modulus increases from 1.08 ± 0.01 to 1.38 ± 0.01 GPa relative to the MFPE. The MFPE / Al2O3 nanofiber composite can be described by a model of weak adhesive interaction of the filler with the matrix with high friction.

Thermodynamic study on levulinic acid in NaCl, (C2H5)4NI and mixed MgCl2/NaCl and CaCl2/NaCl aqueous solutions at T = 298.15 K

Some thermodynamic properties of levulinc acid (LA) were studied under different experimental conditions. The partition coefficient between 2-methyl-1-propanol/pure water (or NaCl aqueous solutions up to I = 1.00 mol dm−3) was measured at T = 298.15 K by means of potentiometric titrations. The protonation constant of levulinic acid was also determined potentiometrically at different ionic strengths in NaCl(aq), (C2H5)4NI(aq) as well as in mixed MgCl2/NaCl and CaCl2/NaCl aqueous solutions.The protonation enthalpy was determined by calorimetric titrations in the same conditions of temperature and ionic strength.The linear fitting of the distribution ratio (log KD) determined at different salt concentrations vs. the salt concentration allowed for the determination of the distribution coefficient at infinite dilution (logKD00 = −0.14 ± 0.02), the Setschenow (km = 0.35 ± 0.03) and the activity coefficient of the neutral species (log γHL = km·msalt). The activity coefficient of the charged L− species was also computed by means of the Specific Interaction Theory (SIT) approach by keeping constant the value of the activity coefficient for the neutral HL species.The medium effect on the protonation constant was also studied using the weak interaction model, namely by comparing the protonation constants obtained in NaCl(aq), (C2H5)4NI(aq) as well as in mixed aqueous MgCl2/NaCl and CaCl2/NaCl mixtures by considering the formation of a NaL(aq), CaL+(aq), and MgL+(aq) species.

Adducts of triangular silver(i) 3,5-bis(trifluoromethyl)pyrazolate with thiophene derivatives: a weak interaction model of desulfurization.

π-Acidic triangular silver(i) 3,5-bis(trifluoromethyl)pyrazolate (Ag3pz3) can form 1 : 1 adducts with dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (DMDBT), benzothiophene (BT), and 2,5-dimethylthiophene (DMT), which are stabilized by weak AgS and AgC contacts and sometimes by π-π stacking and, therefore, may represent a weak interaction model for some adsorptive desulfurization processes.

SA116 - A NOVEL APPROACH TO COMBINE GWAS, PGRS AND GENE-GENE INTERACTIONS IN PSYCHIATRY

Background Studies in psychiatric genetics have focused almost solely on single-loci and polygenic associations and have not included possible interactions. Nicodemus et al. (2014, JAMA Psychiatry) introduced a novel statistical model that incorporates single marker, polygenic and epistatic components to assess the association between SNPs in the ZNF804A pathway and cognitive performance in psychosis. Two-SNP interaction modelling was conducted to test for epistasis. This resulted in a regression model that contained the polygenic score and two two-SNP interaction terms, where the epistatic component explained more variation in cognition than the polygenic score. This model is still relatively simplistic in modelling the genetic architecture of complex traits; in particular, the epistatic component, as the model only allowed for pairwise interactions between SNPs. We sought to implement a more flexible specification of the epistatic component by the use of non-parametric rule sets via the algorithm C5.0. Methods As a proof-of-principle we simulated multiple phenotypes using SNPs located on chromosome 19 explaining A) 30% polygenic variation B) 30% epistatic variation using 2-SNP models not included in the polygenic set, not in LD and under weak (β=0.09), intermediate (β=0.15) and strong (β=0.24) interaction strength and C) a combination containing both a polygenic and epistatic component. Five hundred replicates were simulated per condition. We applied C5.0 in an effort to detect these epistatic interactions. C5.0 is a non-parametric algorithm to generate decision tree-based rulesets. Because of its decision tree basis C5.0 only allows for the Boolean operator OR but does allow for non-binary predictors. Each possible combination from the top node to bottom node in the tree is a so-called ruleset and can be used as a predictor in a regression model. Results We found C5.0 is highly capable of detecting both epistatic SNPs in 100% of the 500 simulations of the strong interaction, 99.2% of the intermediate interaction and 19.2% of the weak interaction models. For the intermediate and weak interactions C5.0 detected only one of the two epistatic SNPs in 0.8% and 41.2% of the replicates. C5.0 was immune to detecting polygenic additivity at the single SNP level. In the polygenic setting of 30% variation explained by an additive effect, C5.0 detected in 11.4% simulations at least one ruleset with no SNP being included more than 13 times Discussion These results show that C5.0 is able to detect epistasis even in the presence of a phenotype containing strong-single loci and polygenic components. Further work includes creating an R package that embeds these different components through a penalised regression framework to combine all three types of genetic variation (single loci, polygenic components, epistatic components) to better reflect the underlying biology, and to apply this method to cognitive performance in Major Depressive Disorder.

Non-Relativistic Limit of Neutron Beta-Decay Cross-Section in the Presence of Strong Magnetic Field

One of the most important reactions of the URCA that lead to the cooling of a neutron star, is neutron beta-decay ( ). In this research, the energy spectra and wave functions of massive fermions taking into account the Anomalous Magnetic Moment (AMM) in the presence of a strong changed magnetic field are calculated. For this purpose, the Dirac-Pauli equation for charged and neutral fermions is solved by Perturbation and Frobenius series method, respectively. The results of the Frobenius series method are in good agreement with the results of Nikiforov-Uvarov method (NU). In continuous, using the calculated wave functions, the general relation of neutron decay cross-section in the non-relativistic limit has been obtained. This relation has been derived by the four-fermion Lagrangian within the framework of the standard model of weak interactions. These calculations from the perspective of nuclear astrophysics can be important.

The concept of strongly interacting groups in self-assembly of soft matter.

Amphiphilic molecules in solution typically produce structures coming from cooperative interactions of many synergetically acting functional units. If all essential interactions are weak, the structure can be treated theoretically based on a free energy expansion for small interaction parameters. However, most self-assembling soft matter systems involve strong specific interactions of functional units leading to qualitatively new structures of highly soluble micellar or fibrillar aggregates. Here we focus on the systems with the so-called strongly interacting groups (SIGs) incorporated into unimer molecules and discuss the effects of packing frustrations and unimer chirality as well as the origins of spontaneous morphological chirality in the case of achiral unimers. We describe several theoretical approaches (overcoming the limitations of weak interaction models) including the concepts of super-strong segregation, geometrical mismatch and orientational frustration. We also review some recently developed phenomenological theories of surfactant membranes and multiscale hierarchical approaches based on all-atomic modeling of packing structures of amphiphilic molecules with SIGs. In particular, we discuss self-assembling structures in systems possessing simultaneously several distinct types of SIGs: solutions of beta-sheet oligopeptides (showing different fibrillar morphologies), aromatic diamide-ester molecules (forming membranes, helical ribbons and tubules), and triarylamine amide derivatives (producing light-controlled supramolecular nanowires).

Decrypting Strong and Weak Single-Walled Carbon Nanotubes Interactions with Mitochondrial Voltage-Dependent Anion Channels Using Molecular Docking and Perturbation Theory

The current molecular docking study provided the Free Energy of Binding (FEB) for the interaction (nanotoxicity) between VDAC mitochondrial channels of three species (VDAC1-Mus musculus, VDAC1-Homo sapiens, VDAC2-Danio rerio) with SWCNT-H, SWCNT-OH, SWCNT-COOH carbon nanotubes. The general results showed that the FEB values were statistically more negative (p < 0.05) in the following order: (SWCNT-VDAC2-Danio rerio) > (SWCNT-VDAC1-Mus musculus) > (SWCNT-VDAC1-Homo sapiens) > (ATP-VDAC). More negative FEB values for SWCNT-COOH and OH were found in VDAC2-Danio rerio when compared with VDAC1-Mus musculus and VDAC1-Homo sapiens (p < 0.05). In addition, a significant correlation (0.66 > r2 > 0.97) was observed between n-Hamada index and VDAC nanotoxicity (or FEB) for the zigzag topologies of SWCNT-COOH and SWCNT-OH. Predictive Nanoparticles-Quantitative-Structure Binding-Relationship models (nano-QSBR) for strong and weak SWCNT-VDAC docking interactions were performed using Perturbation Theory, regression and classification models. Thus, 405 SWCNT-VDAC interactions were predicted using a nano-PT-QSBR classifications model with high accuracy, specificity, and sensitivity (73–98%) in training and validation series, and a maximum AUROC value of 0.978. In addition, the best regression model was obtained with Random Forest (R2 of 0.833, RMSE of 0.0844), suggesting an excellent potential to predict SWCNT-VDAC channel nanotoxicity. All study data are available at https://doi.org/10.6084/m9.figshare.4802320.v2.

Weak localization and interaction effects in acceptor graphite intercalation compounds

The presented work is devoted to investigations of manifestation of quantum effects of weak localization and interaction of charge carriers in electrical conductivity of acceptor graphite intercalation compounds (CICs). As shown by studies intercalation leads to a decrease in the resistivity and to change the resistivity temperature coefficient from negative sign in the source graphite on a positive sign in intercalated graphite. At the low temperature for all GICs specimens the minimum in the temperature dependence of resistivity is observed. In terms of the model of charge carrier's weak localization and interaction for two-dimensional systems temperature dependence of phase relaxation time, localization radius and charge carriers screening constant for all GICs are estimated.

Acid–Base and Thermodynamic Properties ofd-Gluconic Acid and Its Interaction with Sn2+and Zn2+

In this paper, new potentiometric, calorimetric, and voltammetric measurements are reported to model the behavior of d-gluconic acid in aqueous NaCl(aq) and NaNO3(aq) ionic media at different ionic strengths and temperatures (283.15 ≤ T/K ≤ 318.15) also in the presence of Sn2+ and Zn2+. The protonation constants of d-gluconic acid (Gluc– in its deprotonated form) in NaCl(aq) and NaNO3(aq) are very similar. The dependence on ionic strength of the protonation constant was modeled by means of the extended Debye–Huckel type equation, the Specific ion Interaction Theory (SIT) and a weak interaction model. At infinite dilution and T = 298.15 K, the thermodynamic parameters for the proton binding reaction, determined by direct calorimetric titrations and temperature gradients of protonation constants, are log KH0 = 3.709 ± 0.004, ΔG0 = −21.18 ± 0.01 kJ mol–1, ΔH0 = −4.56 ± 0.04 kJ mol–1, and TΔS0 = 16.6 ± 0.1 kJ mol–1, indicating that the reaction is exothermic and entropic in nature. Potentiometric and voltamme...

The Venus–solar wind interaction: Is it purely ionospheric?

The Venus solar wind interaction is often regarded as the prototypical example of an induced magnetosphere. Pioneer Venus Orbiter (PVO) observations during a period of moderate to strong solar EUV fluxes led to a fairly detailed picture in which the currents in the conducting ionosphere produce a nearly impenetrable obstacle to the incident magnetized plasma flow, resulting in a classical draped field magnetosheath region and a comet-like magnetotail. Inspired by the availability of Venus Express (VEX) observations from the north polar region, and their sometimes unexpected behavior, we reanalyzed the observed Venus wake magnetic fields in the altitude range ~150 to ~450km to determine whether some signature of a weak planetary field could have been missed. Our results suggest the presence of a small (few nT) but persistent radial field direction bias in the deep nightside, low to mid-latitude range sampled on PVO. The bias has a hemispheric dependence, with the more positive (outward) fields in the south and the more negative (inward) fields in the north. However the VEX counterpart of these data, obtained just nightward of the north polar terminator, shows no significant bias. This observation raises several questions about our understanding of the fields at the surface of Venus. We investigate whether the PVO radial field bias could be the subtle signature of a weak global dipole with , higher by ~10× than the previously established upper limits. A weak dipole solar wind interaction model produces results in the center of the low altitude wake that compare favorably with the observed field bias seen by PVO; however, the lack of agreement with the higher latitude and VEX observations suggests other explanations need to be considered. For example, effects related to previously observed convection electric field-controlled hemispheric asymmetries provide a possible alternative, as are external fields that diffuse into and through the interior. This work points out the need for better understanding the features introduced by species-dependent plasma processes, and the role of the planet itself, in deciphering weakly magnetized planet interactions.

MAP, MAC, and vortex-rings configurations in the Weinberg–Salam model

We report on the presence of new axially symmetric monopoles, antimonopoles and vortex-rings solutions of the SU(2)×U(1) Weinberg–Salam model of electromagnetic and weak interactions. When the ϕ-winding number n=1, and 2, the configurations are monopole–antimonopole pair (MAP) and monopole–antimonopole chain (MAC) with poles of alternating sign magnetic charge arranged along the z-axis. Vortex-rings start to appear from the MAP and MAC configurations when the winding number n=3. The MAP configurations possess zero net magnetic charge whereas the MAC configurations possess net magnetic charge of 4πn/e.In the MAP configurations, the monopole–antimonopole pair is bounded by the Z0 field flux string and there is an electromagnetic current loop encircling it. The monopole and antimonopole possess magnetic charges ±4πnesin2θW respectively. In the MAC configurations there is no string connecting the monopole and the adjacent antimonopole and they possess magnetic charges ±4πne respectively. The MAC configurations possess infinite total energy and zero magnetic dipole moment whereas the MAP configurations which are actually sphalerons possess finite total energy and magnetic dipole moment. The configurations were investigated for varying values of Higgs self-coupling constant 0≤λ≤40 at Weinberg angle θW=π4.

Half-monopole in the Weinberg–Salam model

We present new axially symmetric half-monopole configuration of the SU(2)×U(1) Weinberg–Salam model of electromagnetic and weak interactions. The half-monopole configuration possesses net magnetic charge 2π/e which is half the magnetic charge of a Cho–Maison monopole. The electromagnetic gauge potential is singular along the negative z-axis. However the total energy is finite and increases only logarithmically with increasing Higgs field self-coupling constant λ1/2 at sin2θW=0.2312. In the U(1) magnetic field, the half-monopole is just a one dimensional finite length line magnetic charge extending from the origin r=0 and lying along the negative z-axis. In the SU(2) ’t Hooft magnetic field, it is a point magnetic charge located at r=0. The half-monopole possesses magnetic dipole moment that decreases exponentially fast with increasing Higgs field self-coupling constant λ1/2 at sin2θW=0.2312.

Thermodynamics for proton binding of phytate in KNO3(aq) at different temperatures and ionic strengths

Potentiometric measurements were performed in KNO3(aq), to determine the apparent protonation constants of phytate at different temperatures (278.15≤T (K)≤323.15) and ionic strengths (0.25≤I (mol)dm−3≤3.0) values. In general, the protonation constants decrease with increasing both temperature and ionic strength. The data reported were critically compared with previous results obtained in KCl and the values are in a good agreement, considering the experimental errors and slight differences between the activity coefficients of the various species in KCl and KNO3. Experimental data were then modeled as a function of temperature and ionic strength using, with comparable results, two approaches: the extended Debye–Hückel equation and the specific ion interaction theory (SIT). The single specific ion interaction coefficients, ɛ, were also determined. The corresponding values are higher than those in Na+ media. The protonation constants were also analyzed considering a simplified weak interaction model using an empirical equation that contains an additional term which takes into account the formation of weak complexes. The results obtained for the modeling of the protonation constants are in agreement with the literature findings.Thermodynamic protonation parameters were also obtained at different temperatures and ionic strengths. The proton association process is slightly exothermic and the enthalpic contribution is less negative than that in NaCl solution. As observed in other cases for phytate anion, the major contribution for the proton association is entropic in nature. A rough value of Δcp was also determined. Finally, a complete set of suggested data is proposed at different temperatures and ionic strengths.

High-precision half-life measurements of atomic nuclei

In a series of measurements performed at the IGISOL facility at the Accelerator Laboratory of the University of Jyvaskyla, the half-lives of 26Si, 29P, 30,31S, 42Ti and 62Ga were measured with high precision. These half-lives are important ingredients for tests of the weak-interaction standard model and allow, together with other experimental inputs and theoretical correction terms, the determination of the vector coupling constant of the weak interaction. The IGISOL method used in Jyvakyla is an ideal tool for these measurements as it allows to access all elements without distinction of their chemical properties.

Physics Beyond the Standard Model with Trapped Cold Atoms

The motivation to study physics beyond the Standard Model of weak interactions is presented and ways to carry out such studies using cold atoms are described. Measurements leading to searches for non-Standard Model scalar and tensor interactions, searches for right-handed neutrinos and for time-reversal violations are described. The searches are done using precision measurements of β decay of cold trapped radioactive atoms and cold neutrons.

Modelling of ionic interactions with wastewater treatment biomass

Titration data for samples of mixed salts with glycine, baker's yeast cell mass and anaerobic digester sludge were obtained and compared to a speciation model of weak acid-base interaction in aqueous solutions. The effect of glycine on the buffer intensity of the solution could be precisely described by the speciation model but did not represent the proton exchange characteristics of either baker's yeast or anaerobic sludge well. A model component, UKZiNe, consisting of carboxylic acids, phosphate and amine groups described the baker's yeast well, and a combination of UKZiNe and carbonate-yielding inorganic solids described anaerobic digester sludge. The effect of biomass on buffer intensity in the pH range 6.5 to 8 was small for the concentration ranges tested.