Anchor Positions Research Articles

Beach Chair Versus Lateral Decubitus Position: Differences in Suture Anchor Position and Number During Arthroscopic Anterior Shoulder Stabilization

Background: Arthroscopic shoulder capsulolabral repair using glenoid-based suture anchor fixation provides consistently favorable outcomes for patients with anterior glenohumeral instability. To optimize outcomes, inferior anchor position, especially at the 6-o’clock position, has been emphasized. Proponents of both the beach-chair (BC) and lateral decubitus (LD) positions advocate that this anchor location can be consistently achieved in both positions. Hypothesis: Patient positioning would be associated with the surgeon-reported labral tear length, total number of anchors used, number of anchors in the inferior glenoid, and placement of an anchor at the 6-o’clock position. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study was a cross-sectional analysis of a prospective multicenter cohort of patients undergoing primary arthroscopic anterior capsulolabral repair. Patient positioning in the BC versus LD position was determined by the operating surgeon and was not randomized. At the time of operative intervention, surgeon-reported labral tear length, total anchor number, anchor number in the inferior glenoid, and anchor placement at the 6-o’clock position were evaluated between BC and LD cohorts. Descriptive statistics and between-group differences (continuous: t test [normal distributions], Wilcoxon rank sum test [nonnormal distributions], and chi-square test [categorical]) were assessed. Results: In total, 714 patients underwent arthroscopic anterior capsulolabral repair (BC vs LD, 406 [56.9%] vs 308 [43.1%]). The surgeon-reported labral tear length was greater for patients having surgery in the LD position (BC vs LD [mean ± SD], 123.5°± 49° vs 132.3°± 44°; P = .012). The LD position was associated with more anchors placed in the inferior glenoid and more frequent placement of anchors at the 6-o’clock (BC vs LD, 22.4% vs 51.6%; P < .001). The LD position was more frequently associated with utilization of ≥4 total anchors (BC vs LD, 33.5% vs 46.1%; P < .001). Conclusion: Surgeons utilizing the LD position for arthroscopic capsulolabral repair in patients with anterior shoulder instability more frequently placed anchors in the inferior glenoid and at the 6-o’clock position. Additionally, surgeon-reported labral tear length was longer when utilizing the LD position. These results suggest that patient positioning may influence the total number of anchors used, the number of anchors used in the inferior glenoid, and the frequency of anchor placement at the 6 o’clock position during arthroscopic capsulolabral repair for anterior shoulder instability. How these findings affect clinical outcomes warrants further study. Registration: NCT02075775 (ClinicalTrials.gov identifier)

Parametric study of structural parameters affecting seismic stability in slopes reinforced by pile-anchor structures

Parametric study was performed on the seismic stability of pile-anchor slope reinforcement structures for earth retaining wall with different structural parameters. Dynamic finite element analysis and the Newmark permanent displacement method were combined to derive the dynamic time-history response of the pile-anchor structure and evaluate slope seismic stability. The effects of pile embedment, pile thickness, anchor position on the pile, anchor free length, anchor direction and anchor prestress were investigated by batch calculation under different structural conditions, and optimized design suggestions are proposed based on the numerical study. The quantitative analysis indicates that Newmark permanent displacement can effectively evaluate slope stability under seismic loading and provide an accessible approach to improve the performance-based design of pile-anchor structures. For the generalized vertical soil slope prevalent in actual slope engineering, considering the maximum factor of safety and minimum permanent displacement, it was found that the most optimized embedded depth occupies approximately 30% of the whole pile length in the soil slope, and the pile thickness is set as 1.5–2 m for superior shear and bending strength. In addition, there is a critical anchor position 3 m beneath the pile top, a threshold free length of the anchor cable of 9.5 m, as well as an optimal direction within the range of 15°–20°. Furthermore, the pile-anchor structure shows better sliding resistance with rational anchor prestress accounting for 20% of the sliding force. The slope seismic stability evaluation based on dynamic finite element analysis with different pile-anchor structural parameter conditions performed in this paper may lay a foundation for the design optimization of pile-anchor reinforcement structures for better dynamic performance.

Calibration method of anchor position in indoor environment based on two-step extended Kalman filter

In this paper, a calibration method based on a two-step extended Kalman filter (EKF) is proposed. Firstly, the four vertex positions of a rectangle in the environment are calibrated. Specifically, in the first stage the initial position states of all anchor nodes are obtained using a rough localization method. In the second stage, the first and second step EKFs are used to obtain the real-time state of the measured target and all anchor nodes. The state estimation of all anchor nodes is achieved by employing the iterative process of the two-step EKF. The effectiveness and stability of the proposed algorithm are verified by simulations and experiment.

An Analysis of Agriculture Sector of Inclusive Growth in India

Agriculture remains the dominant supporter of the Indian populace. The thriving industry and service sectors depend on the agricultural sector for their development. The inter-linkage among the three sectors could not be undermined at any cost. It is the massive absorbent of the labor force even though the disguised unemployment exists in varied magnitude. The share of agriculture to the GDP has come down from 57.7% in 1950-51 to 32.2% in 1990-91 at the time of liberalization, 24.6% in 2000-2001, 15.7% in 2009-2010 then 17%. In the post-independence era, stagnant production, low productivity, traditional technology, and poor rural infrastructure were the major challenges for the Government. India is principally an agricultural country. The agriculture sector estimates 18.0% of the GDP and employs 52% of the total workforce. There is a continuous steady decay in its presence towards the GDP, and the agriculture sector is losing its shine and anchor position in the Indian economy. The problems with which the Indian agricultural scenario is charged in present times are many. Still, this in no way undermines the interest of the sector and the role it can play in the holistic and inclusive growth of the country. Agriculture is fundamental for the sustenance of an economy, as is food for a human being.

Range-Focused Fusion of Camera-IMU-UWB for Accurate and Drift-Reduced Localization

In this work, we present a tightly-coupled fusion scheme of a monocular camera, a 6-DoF IMU, and a single unknown Ultra-wideband (UWB) anchor to achieve accurate and drift-reduced localization. Specifically, this letter focuses on incorporating the UWB sensor into an existing state-of-the-art visual-inertial system. Previous works toward this goal use a single nearest UWB range data to update robot positions in the sliding window (“position-focused”) and have demonstrated encouraging results. However, these approaches ignore 1) the time-offset between UWB and camera sensors, and 2) all other ranges between two consecutive keyframes. Our approach shifts the perspective to the UWB measurements (“range-focused”) by leveraging the propagated information readily available from the visual-inertial odometry pipeline. This allows the UWB data to be used in a more effective manner: the time-offset of each range data is addressed and all available measurements can be utilized. Experimental results show that the proposed method consistently outperforms previous methods in both estimating the anchor position and reducing the drift in long-term trajectories.

Finite-Element Analysis of Pipelines with Axial Walking and Lateral Buckling

A pipeline is prone to axial movement, called pipeline walking, under heat-up and cooldown cycles. The build-up of axial force along the pipeline can result in the phenomenon referred to as lateral buckling. Walking and lateral buckling can both influence pipeline movement performance and threaten the safety of pipeline systems. The numerical simulation method is adopted to study the pipeline movement laws under walking and buckling interactions. Walking and buckling interactions are classified into three types for different forms of seabed slopes, and corresponding mitigation methods are proposed. The effects of buckling number, route bend, sleeper spacing, and anchor position on the lateral displacement amplitude, axial displacement, and effective axial force (EAF) of the pipeline are analyzed. Criteria for the mitigation methods are proposed based on parameters such as the pipeline end expansion, buckling failure parameter, maximum anchor force, and minimum compressive EAF. The results show that the anchor position has a great influence on the intertransformation of pipeline buckling and walking. The difference in anchor force can reach 51.1% considering different anchor positions.

A Geometric Approach to Noisy EDM Resolution in FTM Measurements

Metric Multidimensional Scaling is commonly used to solve multi-sensor location problems in 2D or 3D spaces. In this paper, we show that such technique provides poor results in the case of indoor location problems based on 802.11 Fine Timing Measurements, because the number of anchors is small and the ranging error asymmetrically distributed. We then propose a two-step iterative approach based on geometric resolution of angle inaccuracies. The first step reduces the effect of poor ranging exchanges. The second step reconstructs the anchor positions, starting from the distances of highest likely-accuracy. We show that this geometric approach provides better location accuracy results than other Euclidean Distance Metric techniques based on Least Square Error logic. We also show that the proposed technique, with the input of one or more known location, can allow a set of fixed sensors to auto-determine their position on a floor plan.

Effect of flame holder temperature on the instability modes of laminar premixed flames

Direct Numerical Simulations (DNS) and theoretical analysis of combustion instabilities in laminar premixed flames are performed to investigate the effect of flame holder temperature (Tc) on the self-excited instability modes. Four flames with different anchor positions and recirculation zones are triggered to be unstable by increasing acoustic losses at the boundaries. At Tc = 300 K and 773 K, intrinsic thermo-acoustic (ITA) modes dominate the oscillation frequencies both in anechoic and acoustic systems. The instability modes are mainly determined by the flame characteristics, and significantly affected by the recirculation zone and flame holder. At Tc = 400 K and 1500 K, the instability modes are mainly determined by the couplings between acoustic and ITA modes, and significantly affected by the flame characteristics and system acoustic modes. The dominant oscillation frequencies are closed to the acoustic modes at Tc = 400 K, but in low frequency ranges at Tc = 1500 K. These results indicate that the ITA modes affect the combustion instability in different ways with different flame characteristics. It may cause intrinsic instability or couple with acoustic modes to cause new instability modes. In realistic combustion systems, the ITA modes must be considered carefully in the analysis of combustion instability.

AN ANALYSIS OF AGRICULTURE SECTOR OF INCLUSIVE GROWTH IN INDIA

AN ANALYSIS OF AGRICULTURE SECTOR OF INCLUSIVE GROWTH IN INDIA Dr.P.CHENNAKRISHNAN, Assistant Professor, Department of Economics, Thiruvalluvar University, Serkkadu Vellore -632 Tamil Nadu. 115.drchenna79@gmailcom, 8940600667. Abstract Agriculture remains the dominant supporter of Indian populace. The thriving industry and service sectors depend on the agricultural sector for their development. The inter-linkage among the three sectors could not be undermined at any cost. It is the massive absorbent of labour force even though the disguised unemployment exists in varied magnitude. The share of agriculture to the GDP has come down from 57.7% in 1950-51 to 32.2% in 1990-91 at the time of liberalization, 24.6% in 2000-2001, 15.7% in 2009-2010 and little more than 17%. In the post-independence era, stagnant production, low productivity, traditional technology, and poor rural infrastructure were the major challenges for the Government. India is principally an agricultural country. The agriculture sector accounts for about 18.0% of the GDP and employs 52% of the total workforce. There is a continuous steady decline in its contribution towards the GDP, and the agriculture sector is losing its shine and anchor position in Indian economy. The problems with which the Indian agricultural scenario is burdened in present times are many but this in no way undermines the importance of the sector, and the role it can play in the holistic and inclusive growth of the country. Agriculture is fundamental for sustenance of an economy as is food for a human being.

Analysis of Anchored Sheet Pile Wall Using Finite Element Method

A numerical parametric study using the finite element program of OPTUM G2 was performed on single, double, and triple anchored sheet piles systems retaining sandy soil. The present paper evaluates the variation of maximum shear force distribution, bending moment distribution, and displacement of soil and sheet pile wall concerning different depths of excavation, embedded depth of sheet pile wall, and position of anchor in retention system. Flexible plate elements, Mohr-coulomb sand is considered for modeling of sheet pile wall and soil respectively. The maximum displacement of soil and sheet pile wall for various models are calculated by considering 6-node gauss elements and by using elastoplastic analysis. This method governs the stability of structures in terms of settlement criteria. This analysis also shows the possible potential failure of shear dissipation at different conditions in soil structure. Keywords: Finite element method, Sheet pile, Anchor, Elastoplastic analysis, Bending moment, Shear force, Optum G2.

The USGT Method for Suspender Tensioning of Self‐Anchored Suspension Bridges

Unlike earth‐anchored suspension bridges, self‐anchored suspension bridges (SASBs) involve a special construction stage, namely, suspender tensioning, in which the tensioning force and sequence are crucial and complicated. Against this background, an example bridge A, a SASB with a steel‐concrete composite beam, is introduced in detail. Using MIDAS finite element software, a suspender tensioning scheme is formulated based on a combination method of the unstrained state method and graded tension method (the USGT method), in which a suspender is tensioned according to its unstrained length. By analyzing the bending moment change of the beam and deflection of the main cable throughout the entire construction process, a “high‐to‐low” suspender tensioning sequence is proposed that also involves symmetrical tensioning from the main towers to the midspan or the anchor positions. In the optimized construction process, the deviation and stress of the main towers are controlled well, thereby ensuring the safety of the main beam and main towers in the construction process.

Modeling and Analysis of a Large-Scale Double-Level Guyed Mast for Membrane Antennas

This paper proposes a double-level guyed membrane antenna for stiffness improvement of a large-scale tri-prism deployable mast using the collapsible tubular mast (CTM). Initially, the construction of the antenna and the modeling of the CTM boom are illustrated. Afterwards, the central mast with isosceles triangular cross section is mathematically equivalent to a continuum beam, in which the equations of motion and the constitutive relations are derived. Based on the equivalent central beam, the double-level guyed mast for the membrane antenna is modeled as a 2(3-SPS-S) mechanism, and then velocity Jacobian matrices and stiffness matrices of SPS branches are constructed. Additionally, the total stiffness matrix of the equivalent mechanism is derived with the principle of virtual work and then evaluated as an accurate approach. Finally, with the aim to improve the static stiffness of the double-level guyed mast, the numerical analysis using the Genetic Algorithm (GA) is carried out for optimizing the distribution of guys in terms of anchor positions and attachment heights.

Perceived vs. true glenoid anchor placement: a cadaveric comparison of the beach chair and lateral position.

PurposeTo explore whether patient position influences a surgeon’s ability to accurately judge anchor position on the glenoid.Materials and MethodsTwo anchors were inserted into the glenoid of 8 shoulders. Arthroscopic videos were taken from 3 views (posterior beach chair [pBC], posterior lateral decubitus [pLD], and anterosuperolateral decubitus [asLD]). The shoulders were disarticulated to identify “true” anchor position. Seventeen shoulder surgeons reviewed the videos and indicated anchor positions using the “clock face” method. Accuracy was measured within tolerances, ranging from zero (exact), 0.5 (half-hour), 1.0, and 1.5 hours of “true” position. Intra- and inter-rater agreement was calculated. Post hoc analyses explored for bias dependent on surgical side.ResultsThe overall accuracy was 34.0%. At tolerances of 0.5, 1.0, and 1.5 hours, accuracy increased to 82.4%, 95.4%, and 98.0%. With a 30° scope, identification of exact position was more accurate in pBC than pLD (odds ratio [OR] = 1.397; P = .029) but not asLD (OR =1.341; P = .197). At a tolerance of 0.5 hour, the 30° scope was more accurate in pBC than both pLD (OR = 1.444; P = .011) and asLD (OR = 1.728; P = .009). In left shoulders, anchors were perceived as more inferior than true position in asLD and pLD. In right shoulders, anchors were perceived as more superior than true position from pBC and pLD. Inter- and intrarater agreement were highest in pBC with a 30° scope (30° scope weighted kappa = 0.783 and 70° scope weighted kappa = 0.853, respectively).ConclusionJudgment of anchor position on video is most accurate in a pBC view. Inter- and intrarater reliability were also highest from a pBC view.

Peptide Binding to HLA-E Molecules in Humans, Nonhuman Primates, and Mice Reveals Unique Binding Peptides but Remarkably Conserved Anchor Residues.

Ag presentation via the nonclassical MHC class Ib molecule HLA-E, with nearly complete identity between the two alleles expressed in humans, HLA-E*01:01 and HLA-E*01:03, can lead to the activation of unconventional T cells in humans. Despite this virtual genetic monomorphism, differences in peptide repertoires binding to the two allelic variants have been reported. To further dissect and compare peptide binding to HLA-E*01:01 and HLA-E*01:03, we used an UV-mediated peptide exchange binding assay and an HPLC-based competition binding assay. In addition, we investigated binding of these same peptides to Mamu-E, the nonhuman primate homologue of human HLA-E, and to the HLA-E-like molecule Qa-1b in mice. We next exploited the differences and homologies in the peptide binding pockets of these four molecules to identify allele specific as well as common features of peptide binding motifs across species. Our results reveal differences in peptide binding preferences and intensities for each human HLA-E variant compared with Mamu-E and Qa-1b Using extended peptide libraries, we identified and refined the peptide binding motifs for each of the four molecules and found that they share main anchor positions, evidenced by conserved amino acid preferences across the four HLA-E molecules studied. In addition, we also identified differences in peptide binding motifs, which could explain the observed variations in peptide binding preferences and affinities for each of the four HLA-E-like molecules. Our results could help with guiding the selection of candidate pathogen-derived peptides with the capacity to target HLA-E-restricted T cells that could be mobilized in vaccination and immunotherapeutic strategies.

Markov state modeling reveals alternative unbinding pathways for peptide–MHC complexes

Peptide binding to major histocompatibility complexes (MHCs) is a central component of the immune system, and understanding the mechanism behind stable peptide-MHC binding will aid the development of immunotherapies. While MHC binding is mostly influenced by the identity of the so-called anchor positions of the peptide, secondary interactions from nonanchor positions are known to play a role in complex stability. However, current MHC-binding prediction methods lack an analysis of the major conformational states and might underestimate the impact of secondary interactions. In this work, we present an atomically detailed analysis of peptide-MHC binding that can reveal the contributions of any interaction toward stability. We propose a simulation framework that uses both umbrella sampling and adaptive sampling to generate a Markov state model (MSM) for a coronavirus-derived peptide (QFKDNVILL), bound to one of the most prevalent MHC receptors in humans (HLA-A24:02). While our model reaffirms the importance of the anchor positions of the peptide in establishing stable interactions, our model also reveals the underestimated importance of position 4 (p4), a nonanchor position. We confirmed our results by simulating the impact of specific peptide mutations and validated these predictions through competitive binding assays. By comparing the MSM of the wild-type system with those of the D4A and D4P mutations, our modeling reveals stark differences in unbinding pathways. The analysis presented here can be applied to any peptide-MHC complex of interest with a structural model as input, representing an important step toward comprehensive modeling of the MHC class I pathway.

Front Cover: The Electronic Properties of Ni(PNN) Pincer Complexes Modulate Activity in Catalytic Hydrodehalogenation Reactions (Eur. J. Inorg. Chem. 47/2020)

The Front Cover shows that nickel complexes of new PNN pincer ligands are excellent catalysts for the hydrodehalogenation of aryl halides (bromonaphthalene being shown here) when using NaBH4 as base and hydride source. The potency of the catalysts is enhanced by incorporating an electron-donating group at a para-aryl position of the diarylamido anchor, which becomes evident in comparative studies with less receptive aryl halide substrates. More information can be found in the Full Paper by D. Wang and J. R. Gardinier.

Geometry Investigation and Performance Optimization of a Single-Mass Piezoelectric 6-DOF IMU

This paper explores the fundamental steps towards the development of a 6-axis piezoelectric Inertial Measurement Unit (IMU). The main specification of the reported device is its ability to concurrently detect 3-axis acceleration and angular velocity using a single mass-based design. This work represents a detailed numerical analysis based on a finite element model. Experimental reported data are exploited to validate the FEM model in terms of acceleration detection which is ensured through the direct piezoelectric effect. The angular rate is detected thanks to the Coriolis effect by ensuring drive and sense modes. Using a Finite Element Analysis (FEA), light was shed on the different basic parameters that influence the sensor performance in order to present an optimized design. A detailed geometrical investigation of factors such as anchor position, optimized locations for sensing electrodes, proof-mass dimensions, PZT thickness, and operating frequency is illustrated. The 6-DOF sensor outputs are extracted in terms of the original and the optimized design. The amelioration rate of sensitivity is found to be up to 165% for linear acceleration, while for angular rate sensing, the lateral sensitivity is ameliorated by about 330% and is multiplied by around ten times in the normal axis. The optimized design exhibits a good acceleration sensitivity of 260mV/g in the lateral axis and 60.7mV/g in the z-axis. For angular rate sensing, the new design is more sensitive along the longitudinal axis than the lateral one. Sensitivity values are found to be 2.65µV/rad/s for both x-and y-axis, and 1.24V/rad/s for the z-axis.

A Rapid, SuperSelective Method for Detection of Single Nucleotide Variants in Caenorhabditis elegans.

With the widespread use of single nucleotide variants generated through mutagenesis screens and genome editing technologies, there is pressing need for an efficient and low-cost strategy to genotype single nucleotide substitutions. We have developed a rapid and inexpensive method for detection of point mutants through optimization of SuperSelective (SS) primers for end-point PCR in Caenorhabditis elegans. Each SS primer consists of a 5′ “anchor” that hybridizes to the template, followed by a noncomplementary “bridge,” and a “foot” corresponding to the target allele. The foot sequence is short, such that a single mismatch at the terminal 3′ nucleotide destabilizes primer binding and prevents extension, enabling discrimination of different alleles. We explored how length and sequence composition of each SS primer segment affected selectivity and efficiency in various genetic contexts in order to develop simple rules for primer design that allow for differentiation between alleles over a broad range of annealing temperatures. Manipulating bridge length affected amplification efficiency, while modifying the foot sequence altered discriminatory power. Changing the anchor position enabled SS primers to be used for genotyping in regions with sequences that are challenging for standard primer design. After defining primer design parameters, we demonstrated the utility of SS primers for genotyping crude C. elegans lysates, suggesting that this approach could also be used for SNP mapping and screening of CRISPR mutants. Further, since SS primers reliably detect point mutations, this method has potential for broad application in all genetic systems.

A real case study on the selection of suitable roll stabilizer type for motor yachts using hybrid fuzzy AHP and VIKOR methodology

The comfort of passengers is one of the most important issues on yachts, both during cruising and at anchor position. For this reason, various stabilization equipment is used to minimize the movements resulting from the forces that expose to the yachts at sea. Determining the most suitable stabilization system for a yacht is a challenging multi-criteria decision making (MCDM) problem that requires evaluating many different criteria together. In this study, it is aimed to reveal a hybrid AHP (Analytical Hierarchy Process) and VIKOR (VlseKriterijumska Optimizacijia I Kompromisno Resenje) methodology that can be applied to similar practical problems. A group of decision-makers was asked to evaluate and compare fifteen criteria in the selection of roll stabilizer and evaluate the relationship status of the determined criteria for four alternatives through a questionnaire. The evaluations of the decision-makers were analyzed through the proposed methodology and the results were presented and discussed.

Analysis of 3D localization in underwater optical wireless networks with uncertain anchor positions

Localization accuracy is of paramount importance for the proper operation of underwater optical wireless sensor networks (UOWSNs). However, underwater localization is prone to hostile environmental impediments such as drifts owing to the surface and deep currents. These cause uncertainty in the deployed anchor node positions and pose daunting challenges to achieve accurate location estimations. Therefore, this paper analyzes the performance of three-dimensional (3D) localization for UOWSNs and derives a closed-form expression for the Cramer Rao lower bound (CRLB) by using time of arrival (ToA) and angle of arrival (AoA) measurements under the presence of uncertainty in anchor node positions. Numerical results validate the analytical findings by comparing the localization accuracy in scenarios with and without anchor nodes position uncertainty. Results are also compared with the linear least square (LLS) method and weighted LLS (WLLS) method.