Rotation Of Group Research Articles

The Augmentation of Revision Anterior Cruciate Ligament Reconstruction With Modified Iliotibial Band Tenodesis to Correct the Pivot Shift: A Computer Navigation Study

Background: Iliotibial band (ITB) tenodesis improves stability and functional outcomes when added to anterior cruciate ligament (ACL) reconstruction. Its precise indications are unknown. Persistence of the pivot shift after revision ACL reconstruction may be one indication. Hypothesis: The addition of ITB tenodesis for a persistent pivot shift after revision ACL reconstruction will improve stability and activity levels. Study Design: Cohort study; Level of evidence, 2. Methods: Adults with recurrent ACL ruptures underwent revision ACL reconstruction, followed by a pivot-shift test before the surgery ended. If the pivot shift was grade 0 or 1, no further surgery was performed (group 1). If it was grade 2 or 3, ITB tenodesis was performed (group 2). The pivot-shift test was performed, graded, and measured using computer navigation before revision ACL reconstruction and after revision ACL reconstruction with and without ITB tenodesis. Tegner activity scores were obtained 2 years after surgery. Groups were compared with regard to anterior translation and internal rotation during the pivot shift as well as Tegner activity scores (P < .05). Results: There were 20 patients in group 1 and 18 in group 2. The mean anterior translation improved in group 1, from 17.7 ± 3.5 mm to 6.6 ± 1.9 mm, and group 2, from 18.5 ± 3.3 mm to 6.1 ± 1.2 mm, after revision ACL reconstruction (P < .001), with no difference between the groups (P = .15). After ITB tenodesis, the reduction in anterior translation in group 2 (5.3 ± 1.5 mm) became greater than that in group 1 (6.6 ± 1.9 mm) (P = .03). In both groups after revision ACL reconstruction, there was a reduction in internal rotation (group 1: 24.2° ± 4.0° to 10.3° ± 1.1°; group 2: 25.4° ± 3.7° to 14.6° ± 2.8°; P < .001), but this change was less in group 2 (P = .02). After ITB tenodesis, internal rotation in group 2 (8.3° ± 2.6°) became less than that in group 1 (10.3° ± 1.1°) (P = .02). The mean Tegner activity scores in group 1 were 8.1 ± 1.1 before surgery and 7.4 ± 0.9 after surgery, while in group 2 they were 7.0 ± 1.3 and 7.2 ± 0.4, respectively, and not significantly different (P = .29). Conclusion: ITB tenodesis improved laxity, although it did not affect activity levels, when there was a persistent pivot shift after revision ACL reconstruction. Clinical Relevance: An indication to perform ITB tenodesis is the persistence of a grade ≥2 pivot shift after revision ACL reconstruction.

Efficient Implementation of Variation after Projection Generalized Hartree-Fock.

Projected Hartree-Fock (PHF) theory can restore important symmetries to broken symmetry wave functions. Variation after projection (VAP) implementations make it possible to deliberately break and then restore a given symmetry by directly minimizing the projected energy expression. This technique can be applied to any symmetry that can be broken from relaxing constraints on single Slater determinant wave functions. For instance, generalized Hartree-Fock (GHF) wave functions are eigenfunctions of neither Ŝz nor S2. By relaxing these constraints, the wave function can explore a larger variational space and can reach lower energies than more constrained HF solutions. We have implemented spin-projected GHF (SGHF), which retains many of the advantages of breaking symmetry while also being a spin eigenfunction, with some notable improvements over previous implementations. Our new algorithm involves the formation of new intermediate matrices not previously discussed in the literature. Discretization of the necessary integration over the rotation group SO(3) is also accomplished much more efficiently using Lebedev grids. A novel scheme to incrementally build rotated Fock matrices is also introduced and compared with more standard approaches.

No aggregation-induced-emission but quenching of phosphorescence for an iridium complex with a 2,2-diphenylvinyl motif: a joint experimental and theoretical study.

The diphenylvinyl motif with rotary phenyl rings has been widely used as a building block for the construction of luminescent materials with aggregation-induced emission (AIE) properties. Here, we report the use of 2,2-diphenylvinyl in an iridium complex and its influence on the luminescence properties of the complex. Surprisingly, the 2,2-diphenylvinyl motif attached to the cyclometalating ligand brings about no AIE; instead, it completely quenches the phosphorescence from the iridium complex in solution or films at room temperature or at 77 K. Hydrogenation of the vinyl group in 2,2-diphenylvinyl recovers the phosphorescence. Theoretical calculations reveal that in the lowest triplet state of the complex, the 2,2-diphenylvinyl motif undergoes a significant structural change; as a result, the spin-density in the lowest triplet state distributes almost exclusively on the triphenylethene moiety of the cyclometalating ligand, with little distribution on the iridium ion, leading to complete quenching of phosphorescence. This work reveals that introduction of conjugated molecular motifs with rotational groups (such as 2,2-diphenylvinyl) into iridium complexes should be carefully treated, because it could quench the phosphorescence rather than inducing AIE, which provides a guideline for the design of AIE phosphors based on transition metal complexes.

Effects of Module Development and Role Play Course on Clinical Practice Examination Scores during a 4th Year Clerkship.

BackgroundAfter introduction of clinical skills assessment in the Korean Medical Licensing Examination, medical schools have reinforced both experiential learning with real patients and preparatory programs. This study was conducted to investigate whether a clinical practice examination (CPX) preparation program improves students' CPX score in terms of case specificity.MethodsOne hundred and thirteen senior students in a medical school participated in this study. During the fourth-year clerkship, 28 students (24.8%) from three rotation groups took a 3-day CPX preparation course consisting of module development, role play, and comprehensive physical exam skills training. Eleven rotation groups (n=85) were compared as control. Both the intervention and control group took two comprehensive CPXs before and after the clerkship was completed.ResultsThere was no significant difference in age, sex, and school type between the two groups. On pre-test CPX, there was no significant difference in total and sectional scores between the two groups. On post-test CPX, total scores of the intervention group were higher than those of the control groups (69.5±4.3 vs. 67.5±4.4, P<0.05). History taking scores were higher in intervention groups (70.0±6.0 vs. 66.0±6.6, P=0.01). The station scores of vaginal discharge with case similarity were higher in the intervention groups (73.0±6.3 vs. 68.9±9.3, P=0.03).ConclusionA short CPX preparation course improved history taking ability, but its effect was greater only in a specific case, similar to the pre-course case. Whether this effect was due to the test experience or true improvement in competency requires further investigation.

Erratum: "Approximation by Riesz Means on the Rotation Group SO(3)"

Erratum: "Approximation by Riesz Means on the Rotation Group SO(3)"

The role of teriparatide in tuberosity healing after reverse shoulder arthroplasty in complex proximal humeral fragility fracture.

Tuberosity healing is known to be one of the factors that increase functional outcome in Reverse Total Shoulder Arthroplasty (rTSA). In fragility fractures, tuberosity healing is difficult to be achieved. The fragment stability and bone-forming agent application become strategies to overcome this problem. The purpose of this study was to evaluate the benefit of teriparatide application to promote tuberosity union in rTSA on four-part proximal humeral fractures to achieve better functional outcome. A retrospective study of a prospectively collected shoulder arthroplasty medical record was performed. Eleven patients were included in this analysis and consisted of two groups, teriparatide and no-teriparatide groups. Patients were evaluated on the range of motions and clinical outcome using the American Shoulder Elbow Surgeon (ASES) Shoulder Score and X-ray to determine tuberosity union. The group differences were analyzed by t-test or Mann-Whitney U test with SPSS version 20.0 for Windows. The statistical analysis revealed no significant differences in mean age in both the groups. There were significant differences between teriparatide and no-teriparatide groups in external rotation (29.5° vs. 7.5°; p = 0.004), external rotation in 90° abduction (55° vs. 12.5°; p < 0.020), forward flexion (120° vs. 105°; p = 0.002) range of motions, and ASES (84.5 vs. 74.6; p = 0.019). We found clinical difference between teriparatide and no-teriparatide groups in time to achieve the initial callus (33 ± 18.3 days vs. 150 ± 42.4 days) and tuberosity consolidation (165.8 ± 70.3 days vs. 315 ± 106.1 days). Teriparatide administration supports tuberosity repair results in a high tuberosity healing rate with restoration of external rotation after rTSA in acute complex proximal humeral fractures.

Projective Bivector Parametrization of Isometries in Low Dimensions

The paper provides a pedagogical study on vectorial parameterizations first proposed by O. Rodrigues for the rotation group in $\mathbb{R}^3$ by means of the so-called Rodrigue’s vector. Although his technique yields significant advantages in both theoretical and applied context, the vectorial interpretation is easily seen to be completely wrong and in order to benefit most from this otherwise fruitful approach, we put it in the proper perspective, namely, that of Clifford’s geometric algebras, spin groups and projective geometry. This allows for a natural generalization and straightforward implementations in various physical models, some of which are pointed out below in the text.

Prediction of Pathological Subjects Using Genetic Algorithms.

This paper aims at estimating pathological subjects from a population through various physical information using genetic algorithm (GA). For comparison purposes, K-Means (KM) clustering algorithm has also been used for the estimation. Dataset consisting of some physical factors (age, weight, and height) and tibial rotation values was provided from the literature. Tibial rotation types are four groups as RTER, RTIR, LTER, and LTIR. Each tibial rotation group is divided into three types. Narrow (Type 1) and wide (Type 3) angular values were called pathological and normal (Type 2) angular values were called nonpathological. Physical information was used to examine if the tibial rotations of the subjects were pathological. Since the GA starts randomly and walks all solution space, the GA is seen to produce far better results than the KM for clustering and optimizing the tibial rotation data assessments with large number of subjects even though the KM algorithm has similar effect with the GA in clustering with a small number of subjects. These findings are discovered to be very useful for all health workers such as physiotherapists and orthopedists, in which this consequence is expected to help clinicians in organizing proper treatment programs for patients.

Rotation Group Bias In Current Smoking Prevalence Estimates Using TUS-CPS

This paper examined whether the sample rotation scheme of the Current Population Survey (CPS) results in an underestimation of current smoking prevalence in the Tobacco Use Supplement to the Current Population Survey (TUS-CPS). The TUS-CPS has been administered as part of the CPS, which has eight rotation groups of households in each month that are repeatedly interviewed based on a sample rotation scheme. Previous research has found that even though all eight rotation groups in the CPS are independent random samples of the population, some estimates, such as unemployment rates, tend to be significantly higher in the first rotation group than among other rotation groups. The probit regression results of this paper showed that although current smokers are more likely to attrite than nonsmokers in all years of the TUS-CPS, for the six waves of TUS-CPS before 2003 there is no evidence that current smoking prevalence estimates were significantly affected by the rotation scheme of the CPS. For the three waves of TUS-CPS since 2003, however, the results showed that current smoking prevalence has been underestimated likely due to panel attrition. It appears that rotation group bias in these waves was caused by the substantially increased number of additional questions smokers had to answer.

Invariant singular minimal surfaces

We classify all singular minimal surfaces in Euclidean space that are invariant by a uniparametric group of translations and rotations.

Molecular Viscosity Sensors with Two Rotators for Optimizing the Fluorescence Intensity‐Contrast Trade‐off

AbstractInvited for the cover of this issue is the collaborative team of the groups of O‐Pil Kwon at Ajou University, Chang‐Lyoul Lee at Advanced Photonics Research Institute (APRI), Gwangju Institute of Science and Technology (GIST), Sehoon Kim at Korea Institute of Science and Technology (KIST), Hoseop Yun at Ajou University, and Sang Kyu Kwak at Ulsan National Institute of Science and Technology (UNIST). The image depicts fluorescent molecular rotors by introducing two rotational groups with high fluorescence contrast and cellular fluorescence imaging for mapping cellular viscosity. Read the full text of the article at 10.1002/chem.201704036.

19. Blurred margins to fight recurrent cancer

Introduction Pre-treatment image guidance and intensity modulated radiation therapy allowed for decreasing margins for the planning target volume and sharper dose gradients for better sparing of sensitive healthy organs. However, the number of patients who present with recurrence of previously radiation treated cancer is not decreasing in spite of all improvements in technology. In a search for possible reasons, we investigated the correlation between a broad range of patient specific data, radiation therapy parameters and treatment outcomes for liver cancer patients. Methods Selected patient information was collected from 195 liver cancer patients treated at our centre. Outcome information included survival, disease recurrence, and blood work. All radiation therapy planning parameters were included in the analysis [1] . Patients were split into two almost equal groups: rotational delivery (RD) and fixed beam delivery (FB). Predictive models were created using Cox regression for both survival and recurrence data. Results Predictive model has been developed for liver cancer patients treated with radiation therapy. Even with almost twice the average GTV size, the RD group showed comparable survival and time to recurrence as the FB group. Our data suggest that sufficient dose to the healthy tissue around the tumour improves disease free survival if rotational delivery of radiation is used: Fig. 1 . Only parameter describing normal tissue irradiation V24 had a significant positive effect on disease free survival (DFS) for the rotational delivery group with a hazard ratio (HR) of 0.495. Conclusions In order to prevent disease recurrence, some (optimum to be determined) radiation dose is needed to kill the spread of cancer cells outside the planning target volume. Rotational delivery creating dose splash in all directions does it better than fixed beams.

Occupational Career Change and Gender Wage Inequality

This article examines the relationship between the changing occupational careers of female wage earners and gender wage inequality. Using Current Population Survey-Merged Outgoing Rotation Group data, it assesses the effect on the gender wage gap of changes in the composition and price both of care-providing occupations that are culturally associated with female labor and of managerial and professional occupations that are not part of the care economy, over the period 1979 to 2015. It finds that the rapid entry of female workers into high-wage managerial occupations, and their exit from low-wage private household work, contributed to gender wage convergence. However, the wage-equalizing effects of occupational shifts and related behavioral changes diminish over time, and wage convergence ceases after 2007. It also finds that female workers continue to be disadvantaged by wage dispersion and that most of the remaining gender wage gap arises within occupations. The concluding sections discuss the findings and their implications for closing the wage gap.

The Role of Lumbopelvic-Hip Complex Stability in Softball Throwing Mechanics.

Studies have found that a 20% reduction in energy generation from the lumbopelvic-hip complex during overhead throws leads to a 34% increase in load on the shoulder. The purpose of this study was to assess the effects of lumbopelvic-hip complex stability, via the single leg squat assessment, on throwing mechanics of softball athletes. Prospective cohort study. Laboratory setting. A total of 50 softball athletes (164.0 [104.0]cm, 65.6 [11.3]kg, 16.3 [3.8]y, 8.61 [3.62]y of experience) performed 3 overhead throws and a single leg squat on each leg. Four stability groups were derived: (1)stable on both legs (bilateral stability), (2)unstable on the throwing side leg (TS instability) and stable on the nonthrowing side leg, (3)unstable on the nonthrowing side leg (NTS instability) and stable on the throwing side leg, and (4)unstable on both legs (bilateral instability). All throws were analyzed across 4 throwing events: foot contact (FC), maximum external shoulder rotation (MER), ball release (BR), and maximum internal shoulder rotation (MIR). Mann-Whitney U tests revealed significant differences between the bilateral stability and the TS instability groups in trunk flexion at BR; the bilateral stability and the NTS instability groups in trunk flexion at BR, shoulder horizontal abduction at FC, shoulder rotation at FC, and pelvis flexion at MIR; the TS instability and the bilateral instability groups in trunk rotation at FC; and the NTS instability and the bilateral instability groups in trunk flexion at MER and shoulder rotation at FC. These findings demonstrate the different mechanisms in which energy can be lost through lumbopelvic-hip complex instability as evident in throwing mechanics. The findings from this study suggest that the current methods used for classification could act as a tool for coaches, physicians, and athletic trainers when assessing their athletes' injury susceptibility.

A transverse local feedback linearization approach to human head movement control

In the mid-nineteenth century, Donders had proposed that for every human head rotating away from the primary pointing direction, the rotational vectors in the direction of the corresponding axes of rotation, is restricted to lie on a surface. Donders’ intuition was that under such a restriction, the head orientation would be a function of its pointing direction. In this paper, we revisit Donders’ Law and show that indeed the proposed intuition is true for a restricted class of head-orientations satisfying a class of quadratic Donders’ surfaces, if the head points to a suitable neighborhood of the frontal pointing direction. Moreover, on a suitably chosen subspace of the 3D rotation group SO(3), we describe a head movement dynamical system with input control signals that are the three external torques on the head provided by muscles. Three output signals are also suitably chosen as follows. Two of the output signals are coordinates of the frontal pointing direction. The third signal measures deviation of the state vector from the Donders’ surface. We claim that the square system is locally feedback linearizable on the subspace chosen, and the linear dynamics is decomposed into parts, transverse and tangential to the Donders’ surface. We demonstrate our approach by synthesizing a tracking and path-following controller. Additionally, for different choices of the Donders’ surface parameters, head gaits are visualized by simulating different movement patterns of the head-top vector, as the head-pointing vector rotates around a circle.

Non-scalar operators for the Potts model in arbitrary dimension

We investigate the operator content of the Q-state Potts model in arbitrary dimension, using the representation theory of the symmetric group. In particular we construct all possible tensors acting on N spins, corresponding to given symmetries under and , in terms of representations involving any Young diagram. These operators transform non-trivially under the group of spatial rotations, with a definite conformal spin. The two-point correlation functions are then computed, and their physical interpretation is given in terms of Fortuin–Kasteleyn clusters propagating between two neighbourhoods of each N spins. In two dimensions, we obtain analytically the critical exponent corresponding to each operator. In the simplest and physically most relevant cases, we confirm the values of the critical exponent and the conformal spin by numerical measurements, using both Monte Carlo simulations and transfer matrix diagonalisations. Our classification partially provides the structure of Jordan cells of the dilatation operator in arbitrary dimensions, which in turn gives rise to logarithmic correlation functions.

9,10-Bis((Z)-2-phenyl-2-(pyridin-2-yl)vinyl)anthracene: Aggregation-induced emission, mechanochromic luminescence, and reversible volatile acids-amines switching

Pyridine-containing luminophores have been attracting much attention due to pyridine functions in carrier transport and cation complexation. Here we prepared a butterfly-like molecule 9,10-bis(2-phenyl-2-(pyridin-2-yl)vinyl)anthracene (PyVA) for developing new multifunctional dyes. The multiple rotatable aryl groups enabled PyVA to exhibit a strong aggregation-induced emission effect, and the seriously twisted butterfly-like backbone rendered the solid weak intermolecular π-π interactions and mechanofluorochromism. Quantum chemical calculations indicated that protonation of the pyridyl units could narrow the band gap of PyVA, and X-ray crystallography revealed that PyVA molecules packed in a Z configuration in which the pyridyl units adopted a more twisted conformation with lone N-electron pairs stabilized by intra- and intermolecular CH···N and CH···π interactions. It was observed that both fluorescent crystalline and amorphous PyVA solids could sense volatile acids with a remarkably red-shifted emission, but the amorphous state was more sensitive. Moreover, the acidichromic PyVA solid could further sense volatile amines, and this alternative pH sensitive chromic process was reversible and applicable to fluorescence patterning.

The exponentiated Hencky energy: anisotropic extension and case studies

In this paper we propose an anisotropic extension of the isotropic exponentiated Hencky energy, based on logarithmic strain invariants. Unlike other elastic formulations, the isotropic exponentiated Hencky elastic energy has been derived solely on differential geometric grounds, involving the geodesic distance of the deformation gradient F to the group of rotations. We formally extend this approach towards anisotropy by defining additional anisotropic logarithmic strain invariants with the help of suitable structural tensors and consider our findings for selected case studies.

Cubature Formulas Invariant under the Icosahedral Group of Rotations with Inversion on a Sphere

In this paper, an algorithm of search for the best (in a sense) cubature formulas on a sphere that are invariant with respect to the icosahedral group of rotations with inversion is described. This algorithm is used to find the parameters of all best cubature formulas of this symmetry type up to the 79th degree of exactness. Some parameters of the new cubature formulas of the 21st, 25th, and 29th orders of exactness are given to 16 significant digits.

Special vortex in relativistic hydrodynamics

An exact solution of the Euler equations governing the flow of a compressible fluid in relativistic hydrodynamics is found and studied. It is a relativistic analogue of the Ovsyannikov vortex (special vortex) investigated earlier for classical gas dynamics. Solutions are partially invariant of Defect 1 and Rank 2 with respect to the rotation group. A theorem on the representation of the factor-system in the form of a union of a non-invariant subsystem for the function determining the deviation of the velocity vector from the meridian, and invariant subsystem for determination of thermodynamic parameters, the Lorentz factor and the radial velocity component is proved. Compatibility conditions for the overdetermined non-invariant subsystem are obtained.A stationary solution of this type is studied in detail. It is proved that its invariant subsystem reduces to an implicit differential equation. For this equation, the manifold of branching of solutions is investigated, and a set of singular points is found.