Torsion Components Research Articles

Fragment and torsion biasing algorithms for construction of small organic molecules in proteins using DOCK.

The computational construction of small organic molecules (de novo design), directly in a protein binding site, is an effective means for generating novel ligands tailored to fit the pocket environment. In this work, we present two new methods, which aim to improve de novo design outcomes using (1) biasing algorithms to prioritize selection and/or acceptance of fragments and torsions during growth, and (2) parallel-based clustering and pruning algorithms to remove duplicate molecules as candidate fragment are added. Large-scale testing encompassing thousands of simulations were employed to interrogate the methods in terms of multiple metrics which include numbers of duplicate molecules generated, pairwise-similarity, focused library reconstruction rates, fragment and torsion frequencies, fragment and torsion rank scores, interaction energy and drug-likeness scores, and 3D pose comparisons. The biasing algorithms, particularly those that include fragment and torsion components simultaneously, led to molecules that more closely mimicked the distributions of fragments and torsions found in drug-like libraries. The new parallel-based clustering and pruning algorithms, compared with the existing serial approach, also led to larger ensembles comprised of topologically unique molecules with much greater efficiency by removing redundant growth paths.

Validation of the Cervical Torsion Test and Head-Neck Differentiation Test in Patients With Peripheral Vestibular Hypofunction.

This study compared adults with peripheral vestibular hypofunction (VH) to healthy controls and assessed the sensitivity and specificity of the Cervical Torsion Test (CTT) and the Head-Neck Differentiation Test (HNDT). This study aimed to determine whether neck problems affected primary outcomes. This cross-sectional study included adults from a specialist consultation for dizziness. VH had been diagnosed with the video Head Impulse Test. Exclusion criteria were conditions following head or neck trauma and diseases of the central nervous system. The sensitivity and specificity of the index tests were calculated, and regression analyses were performed to test for contributing factors. A total of 19 patients with VH and a historical cohort of 19 matched healthy controls were included. Most patients with VH (84.2%) experienced symptoms in at least 1 test component, compared to 5.2% of the control group. Of patients with VH, 78.9% had symptoms during the HNDT "en bloc" (en bloc = head and trunk rotated together), whereas only 26.3% reported symptoms during the CTT en bloc. The best discriminatory validity was found for the HNDT en bloc, with a sensitivity of 0.79 (95% CI = 0.54-0.94), a specificity of 0.86 (95% CI = 0.65-0.97), and a positive likelihood ratio of 5.79 (95% CI = 1.97-17.00). The number of symptoms of CTT "in torsion" (in torsion = trunk rotated actively with fixed head) was increased by a factor of 1.13 (95% CI = 1.01-1.27) for every additional point on the Neck Disability Index. The CTT and HNDT can serve as non-laboratory tests for patients with dizziness. The HNDT en bloc has the best discriminatory validity, finding those with and those without VH. Symptom reproduction during torsion may help to identify when neck problems may contribute to dizziness. The HNDT en bloc may be useful for ruling VH in or out in patients with dizziness. Positive CTT and HNDT in torsion components may verify the likelihood of additional neck involvement.

Effective field theories as Lagrange spaces

We present a formulation of scalar effective field theories in terms of the geometry of Lagrange spaces. The horizontal geometry of the Lagrange space generalizes the Riemannian geometry on the scalar field manifold, inducing a broad class of affine connections that can be used to covariantly express and simplify tree-level scattering amplitudes. Meanwhile, the vertical geometry of the Lagrange space characterizes the physical validity of the effective field theory, as a torsion component comprises strictly higher-point Wilson coefficients. Imposing analyticity, unitarity, and symmetry on the theory then constrains the signs and sizes of derivatives of the torsion component, implying that physical theories correspond to a special class of vertical geometry.

Effect of a novel controlled thermomechanical treatment on the microstructure and mechanical properties of a high-carbon nanobainitic steel

The effect of the novel controlled thermomechanical treatment, including torsion components in the elastic strain range during the isothermal holding on the microstructure and mechanical properties of the high-carbon nanobainitic steel, was investigated. TEM observations of the thermo-mechanically treated steel revealed bainitic ferrite laths with an average size of 68 ± 40 nm and films of retained austenite with an average size of 34 ± 17 nm, along with the blocky morphology of retained austenite in sub-micron scale. The XRD synchrotron diffraction allows estimating the amount of retained austenite at 43.1 ± 1.2% volume fraction with a carbon concentration of 1.17 ± 0.09 wt.%. Furthermore, the deconvolution of (200) Fe-γ reflections corresponding to two different low-carbon and high-carbon retained austenite peaks and, simultaneously, the blocky and film-like retained austenite was performed. In addition, the Nishiyama–Wassermann (N–W) crystallographic orientation relationship between bainitic ferrite and retained austenite was described as dominant using the misorientation distribution function (MDF). The crystallographic texture results indicated that the main growth of bainitic ferrite plates occurred after removing external stress during isothermal holding. The tensile tests and hardness measurements showed a high tensile strength achieved mainly by nano-metric bainitic ferrite plates and a high dislocation density. The high level of elongation is most likely attained due to a high amount of retained austenite in steel and both TRIP and TWIP effects during tensile deformation.

КРУЧЕНИЕ НИЖНЕГО ПОЯСА ПОДКРАНОВО-ПОДСТРОПИЛЬНОЙ ФЕРМЫ

The lower belt of the crane secondary truss, along which the crane moves, is made of a thin-walled box profile. The largest local concentrated crane forces applied with eccentricity to the lower belt of truss made of thin-walled welded box cause its restrained torsion. The calculation method of the crane secondary truss does not consider the inclusion in the work of the lower belt for torsion and horizontal bending of the webs. A beam with a span equal to the span of the crane secondary truss is taken as the design scheme of the lower belt along which the crane moves. In fact, the work of the belt during torsion is different from the work of the beam.
 The objectives of the work are to assess the impact on the operation of the lower belt during torsion of the webs and the upper belt and to clarify the methodology for calculating the lower belt. The study of the influence of webs on the angular malleability and torque of the lower belt has been carried out. Various ratios of the stiffness of the belt and the entire crane secondary truss are considered. The design scheme of the belt for the calculation of torsion is proposed – a beam angular elastic supports at the points of junction of the webs. The formula for determining the stiffness of elastic supports has been adopted. The error in determining the bending moments in the lower belt according to the proposed method relative to the results of numerical calculation of the rod design scheme of the entire crane secondary truss does not exceed 2%. The stresses in the lower belt, considering the torsion component, are analytically determined. The results were verified numerically using shell finite elements and a full-scale examination.

Component Rotation in Well-Functioning, Gap Balanced Total Knee Arthroplasty Without Navigation

BackgroundMalalignment of total knee arthroplasty (TKA) components is a potential cause of clinical failure following TKA. Since the goal of a gap balancing (GB) technique is equal flexion and extension gaps secondary to soft-tissue balancing, and not necessarily component alignment, variation in component placement may exist. Our purpose was (1) to evaluate precision of component alignment in well-functioning GB TKAs performed without the aid of navigation using computed tomographic evaluation and (2) to determine any relationship between femoral version and/or tibial torsion and TKA component positioning. MethodsThere were 93 well-functioning TKAs performed with an extension gap first GB technique with a minimum 2-year follow-up evaluated using computed tomography to assess component rotational alignment, as well as osseous femoral version and tibial torsion. Femoral and tibial rotational alignment was assessed by previously described methods. ResultsThe mean Knee Society Score was 185.7 ± 21.7. The mean range of motion was 128.5 ± 7.8°. Femoral posterocondylar axis (relative to the transepicondylar axis) values ranged from −8.3 to 4.1° with a mean of −0.78 ± 2.7° (internal rotation). Mean tibial rotation was 17.2 ± 7.9° internal rotation relative to the tibial tubercle. No correlation was found between native femoral version and femoral component rotational alignment (Pearson’s correlation coefficient, r, 0.007). Weak correlation was found between native tibial torsion and tibial component alignment (r = 0.24). ConclusionDespite being only a secondary objective with the GB technique, most components evaluated were within the desired range of rotation. Alignment was not influenced by native osseous rotational geometry. Level of EvidenceLevel III, Retrospective Cohort Study.

Influence of adjacent segments on the torsional load-bearing behaviour of assembled half-shell towers

This article deals with the influence of adjacent segments on the torsional load bearing behaviour of assembled half-shell towers for wind energy turbines. The main objective is to detect and understand the load transfer in the modular tower structure considering the effects of adjacent segments. The engineering approach already developed for two assembled half-shells – based on the warping theory of thin-walled bars – is investigated for its applicability to the entire tower structure. Numerical comparative studies show that an adjacent half-shell pair level at the top and bottom is sufficient to take the influence of the entire tower structure into account. The adjacent segments affect the quantitative determination of the load-bearing components from shear force and torsion. Furthermore, the coupling conditions in the horizontal joint depend on the stress consideration and include only one (normal stresses via linear superposition) or both half-shells (shear stresses via Bredt shear flow). Therefore, an analytically and numerically based approach is presented that can be applied to the use case of segmental towers for wind turbines and the constant component heights of the precast segments. In this case, the methods take the decrease of the bending shear force component and the simultaneous increase of the torsion component in the system axis into account. The boundary conditions of the frame structure remain unaffected. Based on the further developed engineering model, the complex torsional load-bearing behaviour and the stress state in the horizontal joint of modular tower structures can now be analytically determined in the compressed and static friction condition based on the warping theory of thin-walled bars.

Device for Torsional Fatigue Strength Assessment Adapted for Pulsating Testing Machines.

The torsional fatigue test determines the fatigue limit for a certain asymmetry coefficient of the cycle. The assessment of fatigue tests is performed on specialized machines. There are two types of torsion testing machines: universal machines that have the torsion component and specialized machines only for torsion testing. Nevertheless, no matter which proposed option we choose, the purchase prices for these testing machines or the values spent for self-management are quite high. This paper presented a device used for torsion fatigue testing, adaptable to a universal pulsating testing machine, designed to determine the torsion fatigue limit for different materials. The built device is simple and reliable, and therefore inexpensive. By using this device, we can determine the limit of the torsional fatigue after any stress cycle and we can use the parameters obtained from the universal machine to which it was attached. The torque and twisting angle of the test specimen during the test can be determined by calculation. The paper also presented an experimental method for determining shear strains based on calibration experiment, using a specimen on which strain gauges were mounted. The values taken from this calibration experiment were compared with those obtained from the theoretical calculation.

Einstein’s dream to unify all forces finally materializes: a revived de Broglie’s pilot-wave theory with novel solutions

Starting from Louis de Broglie’s pilot wave-theory, this paper unifies gravity and quantum mechanics under a single mathematical field theory for all forces in Nature. Two families of potentials coexist as mathematical solutions for the homogeneous Klein-Gordon equation which is the same homogeneous classical wave equation: (a) Neo-Laplacian local time-independent background potentials, and (b) Novel time-distance entangled Q(q) potentials which are isomorph to distance-time-velocity transformations based on any of the competing relativistic theories (Lorentz, Poincaré or Einstein), or on the pre-relativistic Galilean invariant Doppler equations. This remarkable property makes present theory compatible with all previous empirical evidence, including experiments conventionally interpreted as supporting Einstein’s special relativity. We report explicit closed solutions for potentials solving the one-dimensional and three-dimensional classical wave equations, and describe in detail how to calculate time-independent neo-Laplacian background forces and relativistically isomorph time-dependent entangled forces. The scale of the problem appears as a required parameter, thus making our theory applicable to all scales of Nature from quarks to cosmos. A usually overlooked neo-Laplacian logarithmic potential predicts the observed high values of non-Keplerian tangential speeds at the galactic scale. At the human scale, calculations relative to hurricanes and tornadoes may be facilitated by the closed form of our unified forces. A novel torsion component of gravity automatically appears from our new solutions.

Surgical treatment of juvenile progressive scoliosis (staged message)

At the Department of Child and Adolescent Vertebrology of Novosibirsk SRI TO a multi-step technique was used for the surgical treatment of 21 patients with progressive juvenile scoliosis. That technique included epiphysiospondylodesis on the convex side of curvature, step by step distraction with endocorrector from the Cotrel-Dubousset instrumentation set and completely posterior spondylodesis at the age of sexual maturation. Six out of 21 patients completed treatment; the deformity was decreased from 74.6 to 41.5 and the achieved correction has been almost completely preserved. That surgical technique did not disturb the growth of patients trunk (mean growth rate was 6 cm per year). Torsion component of the deformity did not increase confirming the efficacy of epiphysiospondylodesis. Mean follow up made up 27 months. In spite of the significant number of complications the obtained results testified the prospectiveness of that direction.

Dynamic response analysis of isolated curved beam bridge under multi-dimensional non-stationary random excitation considering the torsion component

The coupling effect of bending and torsion caused by plane irregularity of the isolated curved beam bridge makes its seismic response more complex than that of the isolated straight beam bridge. In order to study the influence of multi-dimensional non-stationary random excitation considering torsion component on seismic response of tqiongw@mls.sinanet.com he isolated curved beam bridge. The classical Bouc-Wen model was used to simulate the hysteretic characteristics of the curved beam bridge, and the nonlinear dynamic equation considering the eccentricity of superstructure was established. The pseudo excitation was transformed into harmonic external load by Euler formula, and combining with the precise integration method, the precise integration forms of the special solution under different modulation functions were derived. By using these integral forms to solve the response at each time, the time-varying variance of displacement of the isolated curved beam bridge under multi-dimensional non-stationary random excitation was obtained, and the law of time-varying variance of displacement, including the upper and lower structures of the isolated curved beam bridge, was analyzed with different deck width, curvature radius and yield ratio of bearing. The results show that the multi-dimensional non-stationary random excitation with torsion component has significant influence on the seismic response of the isolated curved beam bridge. Under the rare non-stationary random excitation, the dynamic response of the isolated curved beam bridge presents strong non-stationarity, and the time-lag phenomenon is apparent. For the isolated curved beam bridge with large deck width and small yield ratio of bearing, the influence of non-stationary random excitation on the structure is particularly obvious. The influence of non-stationary random excitation considering torsion component on dynamic response of the isolated curved beam bridge with large deck width, small curvature radius and large yield ratio of bearing is more significant.

Monitoring Flexions and Torsions of the Trunk via Gyroscope-Calibrated Capacitive Elastomeric Wearable Sensors.

Reliable, easy-to-use, and cost-effective wearable sensors are desirable for continuous measurements of flexions and torsions of the trunk, in order to assess risks and prevent injuries related to body movements in various contexts. Piezo-capacitive stretch sensors, made of dielectric elastomer membranes coated with compliant electrodes, have recently been described as a wearable, lightweight and low-cost technology to monitor body kinematics. An increase of their capacitance upon stretching can be used to sense angular movements. Here, we report on a wearable wireless system that, using two sensing stripes arranged on shoulder straps, can detect flexions and torsions of the trunk, following a simple and fast calibration with a conventional tri-axial gyroscope on board. The piezo-capacitive sensors avoid the errors that would be introduced by continuous sensing with a gyroscope, due to its typical drift. Relative to stereophotogrammetry (non-wearable standard system for motion capture), pure flexions and pure torsions could be detected by the piezo-capacitive sensors with a root mean square error of ~8° and ~12°, respectively, whilst for flexion and torsion components in compound movements, the error was ~13° and ~15°, respectively.

Einstein–Cartan non-supersymmetric spin-polarised nucleons wall dynamos

Einstein-Cartan (EC) gravity uses as source a spin–spin torsion contact interaction. In this paper we make use EC QCD domain walls with nucleons spins, orthogonally to the wall, as an EC chiral torsion source to investigate magnetogenesis. Dynamo amplification factor of γEU∼10−3GeV is obtained from Early universe torsion of 1 MeV. Early universe torsion and QCD topology also provide us with an estimate of magnetic helicity density of hQCD∼1034G210−3GeV. In this case, helicity in the presence of torsion is stronger than in Minkowskian spacetime. Chiral chemical potential undergoes torsion effects as well, and not only of the Hubble constant. QCD domain wall non-supersymmetric metrics [Jensen, Soleng, CQG (1998)] and Garcia de Andrade (1999), are shown to lead to exact solution of chiral dynamo equations with magnetic fields parallel to the wall due to the chiral magnetic effect (CME). A special type of Einstein-Cartan chiral dynamo solution is found on a dilatonic domain wall, where when torsion vanishes the magnetic field is constant. In this domain wall metric exponents depend only upon torsion components.

Gradient microstructure of Fe-Cr-Co based hard magnetic alloy subjected to complex loading

Creation of gradient structures is of particular importance for industries requiring taylorable set of material properties in the bulk of the material. Among various ways of introducing variable grain size is subjecting the material to the strain mode corresponding to combination of tension and torsion. In this work we compare loading modes associated with varying amounts of tension and torsion components analyzing the microstructure and microhardness of the final product. We establish that the material under torsion is more resistant to localization of deformation in comparison with stretching. It is shown that torsion/tension complex loading can be used for manufacturing cylindrical billets of hard magnetic alloys of the Fe-Cr-Co system with both a gradient structure and a homogeneous microcrystalline structure.

Quantum Field Theory on Noncommutative Curved Space-times and Noncommutative Gravity

In the noncommutative gauge-theoretical formulation of Langman and Szabo, apparently it appears that the torsion generated there is a generalized one i.e. it may containvector, axial vector and tensor components. However, when we transcribe the noncommutative gauge theory in terms of the Maxwell gauge theory using the Seiberg-Wittencorrespondence, we have noted that upto the first order in the noncommutative parameter, this effectively can be taken to induce a change in chiral anomaly and hence theassociated torsion should be an axial vector one. The noncommutative gauge symmetriesgive a very natural and explicit realizations of the mixing of space-time and internal symmetries which is a characteristic feature of the conventional gauge theory of gravity. Thegauge fields of the dimensionally reduced noncommutative Yang-Mills theory map ontoaWeitzenbӧck space time and a teleparallel theory of gravity arises as the zero curvature reduction of a Poincare gauge theory which induces an Einstein-Cartan space-timecharacterized by connections with both nonvanishing torsion and curvature. However, theteleparallelism equivalent of general relativity involves all the components of torsion. Thechiral anomaly in the Einstein-Cartan space U₄ is characterized by the topological invariants like Pontryagin density as well as the Nieh-Yan density when the latter term involvesthe length scale governed by the measure of noncommutativity of space points. It is shownthat we have discussed the equivalence of this formalism with noncommutative U(1) Yang Mills theory.

Seismic response of large-span spatial structures under multi-support and multidimensional excitations including rotational components

To achieve rational and precise seismic response predictions of large span spatial structures (LSSSs), the inherent non-uniformity and multidimensionality characteristics of earthquake ground motions should be properly taken into consideration. However, due to the limitations of available earthquake stations to record seismic rotational components, the effects of rocking and torsional earthquake components are commonly neglected in the seismic analyses of LSSSs. In this study, a newly developed method to extract the rocking and torsion components at any point along the area of a deployed dense array from the translational earthquake recordings is applied to obtain the rotational seismic inputs for a LSSS. The numerical model of an actual LSSS, the Dalian International Conference Center (DICC), is developed to study the influences of multi-support and multidimensional excitations on the seismic responses of LSSSs. The numerical results reveal that the non-uniformity and multidimensionality of ground motion input can considerably affect the dynamic response of the DICC. The specific degree of influence on the overall and local structural displacements, deformations and forces are comprehensively investigated and discussed.

Single hair fiber assessment techniques to discriminate between mineral oil and coconut oil effect on hair physical properties.

To utilize a matrix of single-fiber hair testing methodologies to mechanistically understand the impact of common oiling treatments-coconut oil and mineral oil-on hair strands. Further, the effect of hair twisting-experienced in everyday grooming practices-on hair strength was investigated under different scenarios. Study involved multiple surfactant wash cycles of hair swatches with and without overnight hair oil treatments. Instrumental testing was done on strands from hair swatches-Tensile Extension, Torsional Stretching, and Tensile Extension of twisted hair fibers. Differentiation was observed in tensile and torsional testing parameters with 20 wash cycles, while no statistical significance was observed in single wash. However, when we combine the two stresses together by extending the twisted hair strands, a clear differentiation was seen even in single cycle for coconut oil in comparison with mineral oil and surfactant wash. The differentiation in tensile parameters for twisted fibers becomes much more prominent with multiple cycles. Penetration of coconut oil in hair strands makes the fiber core more flexible and thus helps negotiate the torsional stress at the time of extension. Product benefit discrimination in single-strand testing can be amplified by combining multiple stresses in one testing methodology. Observing the consumer habits and incorporating the torsion component in standard tensile testing of hair helps differentiate the two commonly used hair oiling treatments. Coconut oil was found to significantly increase the tensile strength of twisted fibers owing to its penetration inside hair core.

The cosmological principle in theories with torsion: the case of Einstein-Cartan-Dirac-Maxwell gravity

We address the implementation of the cosmological principle, that is, the assumption of homogeneity and isotropy in the spatial distribution of matter in the Universe, within the context of Einstein-Cartan theory including minimal couplings of both Dirac and Maxwell fields to torsion. This theory gives rise to new physical effects in environments of high spin densities while leaving the vacuum dynamics unaffected. Our approach is to impose the cosmological principle from the onset to the geometrical degrees of freedom (metric and torsion functions), which constrains the torsion components and the corresponding correction terms in the Friedmann-like equations and in the resulting fermionic and bosonic (non-linear) dynamics. We derive the corresponding cosmological dynamics for the geometrical and matter degrees of freedom and discuss the validity of this approach.

Seismic Response Analyses of Transmission Towers under Multidimensional Ground Motions with Rocking and Torsion Components

AbstractMost current studies on the seismic responses of transmission towers are performed using two or three translational components of ground motion as earthquake inputs. In this study, a novel ...

On the extremal compatible linear connection of a Randers space

A linear connection on a Finsler manifold is called compatible to the metric if its parallel transports preserve the Finslerian length of tangent vectors. Generalized Berwald manifolds are Finsler manifolds equipped with a compatible linear connection. Since the compatibility to the Finslerian metric does not imply the unicity of the linear connection in general, the first step of checking the existence of compatible linear connections on a Finsler manifold is to choose the best one to look for. A reasonable choice is introduced in Vincze (J Differ Geom Appl, 2019. arXiv:1909.03096) called the extremal compatible linear connection, which has torsion of minimal norm at each point. Randers metrics are special Finsler metrics that can be written as the sum of a Riemannian metric and a 1-form (they are “translates” of Riemannian metrics). In this paper, we investigate the compatibility equations for a linear connection to a Randers metric. Since a compatible linear connection is uniquely determined by its torsion, we transform the compatibility equations by taking the torsion components as variables. We determine when these equations have solutions, i.e. when the Randers space becomes a generalized Berwald space admitting a compatible linear connection. Describing all of them, we can select the extremal connection with the norm minimizing property. As a consequence, we obtain the characterization theorem in Vincze (Indag Math 26(2):363–379, 2014): a Randers space is a non-Riemannian generalized Berwald space if and only if the norm of the perturbating term with respect to the Riemannian part of the metric is a positive constant.