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Synthetic aperture radar (SAR) can monitor the sea surface imprints of tropical cyclones (TCs) with high spatial resolution, day and night. Automatically locating TC center positions in SAR images is a challenging task. This article developed a two-stage, fully automatic TC-center estimation algorithm. First, the sea surface wind directions (SSWDs) at SSWD points are retrieved by the improved local gradient (ILG) method. We incrementally deflected the SSWD outward at a 0.5° angle from -50° to 10° (the negative angles represent clockwise deflection). The heat maps are generated for each of the 121 angles, and the values at each heat map are the cumulative numbers of the lines perpendicular to the compensated SSWDs. The site corresponding to the maximum cumulative number in all 121 heat maps is the coarsely estimated center position. This center search is the culmination if it falls outside the SAR image. Otherwise, the second stage is triggered, and the sub-SAR image (150 km x 150 km) centered at the coarsely estimated center position is extracted. Then, the first-stage procedure is repeated with the sub-SAR image to precisely estimate the center position. Optionally, the precisely estimated center position can be further adjusted by considering that normalized radar cross section (NRCS) is normally minimal at the TC center. We applied the algorithm to 87 SAR images. Five of these images do not contain TC centers. The results are in good agreement with the visually located TC center positions and those in the best track (BT) datasets.

The aim of this study was to perform a three-dimensional evaluation of the skeletal relapse of the proximal and distal mandibular segments following isolated bilateral sagittal split osteotomy advancement surgery. One hundred consecutive patients (mean age 25.8±11.7 years), comprising 65 female patients (mean age 26.4±12.1 years) and 35 male patients (mean age 24.6±11.0 years) requiring mandibular advancement without genioplasty, were enrolled prospectively in the study. Cone beam computed tomography scans were acquired for each patient at three time-points: preoperatively, immediately (1-6 weeks) after surgery, and 1 year after surgery. A validated tool was utilized to assess the surgical movement and relapse. Based on percentage, the majority of the distal and proximal translational and rotational movements relapsed within the range of ≤2mm and ≤2°. The distal segment revealed a significant relapse in a posterior, inferior, and clockwise pitch direction. Both left and right proximal segments showed a significant translational relapse in the medial, posterior, and superior direction. Amongst the rotational parameters, proximal segments relapsed significantly in clockwise pitch, clockwise roll, and counterclockwise yaw direction. Overall, both distal and proximal bone segments showed a clinically acceptable translational and rotational stability. The proximal segments torqued towards their original position with a reduction of flaring. ispartof: INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY vol:51 issue:1 pages:113-121 ispartof: location:Denmark status: published

Background: The complete left bundle branch block (CLBBB) results in ventricular dyssynchrony and a reduction in systolic and diastolic efficiency. We noticed a distinct clockwise rotation of the left ventricle (LV) in patients with CLBBB (“longitudinal rotation”). Aim: The aim of this study was to quantify the “longitudinal rotation” of the LV in patients with CLBBB in comparison to patients with normal conduction or complete right bundle branch block (CRBBB). Methods: Sixty consecutive patients with normal QRS, CRBBB, or CLBBB were included. Stored raw data DICOM 2D apical-4 chambers view images cine clips were analyzed using EchoPac plugin version 203 (GE Vingmed Ultrasound AS, Horten, Norway). In EchoPac–Q-Analysis, 2D strain application was selected. Instead of apical view algorithms, the SAX-MV (short axis—mitral valve level) algorithm was selected for analysis. A closed loop endocardial contour was drawn to initiate the analysis. The “posterior” segment (representing the mitral valve) was excluded before finalizing the analysis. Longitudinal rotation direction, peak angle, and time-to-peak rotation were recorded. Results: All patients with CLBBB (n = 21) had clockwise longitudinal rotation with mean four chamber peak rotation angle of −3.9 ± 2.4°. This rotation is significantly larger than in patients with normal QRS (−1.4 ± 3°, p = 0.005) and CRBBB (0.1 ± 2.2°, p = 0.00001). Clockwise rotation was found to be correlated to QRS duration in patients with the non-RBBB pattern. The angle of rotation was not associated with a lower ejection fraction or the presence of regional wall abnormalities. Conclusions: Significant clockwise longitudinal rotation was found in CLBBB patients compared to normal QRS or CRBBB patients using speckle-tracking echocardiography.

The study aims to understand geometry and evolution of accommodation zones along restraining and releasing bends in strike slip systems which is often complex and characterized by sharp change in polarity, resulting in a difficult characterization of traps location. A batch of sandbox modelling experiments was performed using a layered scaled sand material. The setup parameters of the wooden baseplates used in the first two experiments (SS1 and SS2) are basement offset of 6.5 cm/3 cm, 90°/90° stepovers in releasing and restraining bends of total 96 cm length and 25 cm width. The third experiment (SS3) was performed with basement offset of 6.5 cm/3 cm, 156°/126° stepovers in releasing and restraining bends of total 96 cm length and 25 cm width. The experiments were performed with special attention to the role of syn-kinematic sedimentation and the pre-existing structure of the basement. A sequence of pop-up and pull-apart structures was produced. Along the main structures, complex fault trend was compatible with a sinistral riedel distribution and a counterclockwise rotation of pre-existent elements. Change of fault's polarity at depth and dip direction flipping of high angle faults in accommodation zones were clearly observed. Even more, progressive propagation of the pop-up structures produces a spectacular inversion of adjacent extensional structures. Comparing results of the model with the Seagap fault zone, it is possible to put in evidence similar fault orientation and distribution. Internal structures developed were strongly influenced by syn-kinematic sedimentation as observed by characteristic helicoidal shape of growth faults. The analogue models clearly describe how boundary faults of the pull-apart basin along a paired bend, initially characterized by a normal kinematic can be subsequently inverted in the later stages, which can potentially have a strong impact on the petroleum system.

Xin He,1 Wei-Hang Zhuang,2 Dong-Liang Zhang1 1Department of Orthodontics, School of Stomatology, Capital Medical University, Beijing, 100050, People’s Republic of China; 2Department of Stomatology, Beijing Rytime Dental Hospital, Beijing, 100024, People’s Republic of ChinaCorrespondence: Dong-Liang ZhangDepartment of Orthodontics, School of Stomatology, Capital Medical University, No. 11 Xila Hutong, Dongcheng District, Beijing, 100050, People’s Republic of ChinaEmail zhangdongliang@hotmail.comAim: To analyze the movement of anterior teeth by changing the height of the power-arm and changing the force application points during whole maxillary dentition distalization with the aid of micro-implants in lingual orthodontics to set a biomechanical reference for effective clinical use of lingual orthodontic appliance.Methods: A three-dimensional finite element model of the maxillary teeth with lingual appliance and the associated support tissue was established. Maxillary dentition with the force of 200g was distalized using implant as anchorage, then the movement of anterior teeth was analyzed by changing the length of power-arm (1mm, 3mm, 6mm, 9mm) and by changing the force location from lingual side to buccal side.Results: During whole maxillary dentition distalization with aid of the implants in lingual orthodontics: when the height of power arm was 1mm, the anterior teeth rotated clockwise, with the increasing of the height of power-arm, the anterior teeth rotated counterclockwise gradually. When the height of power-arm was 9mm, all anterior teeth rotated counterclockwise. Central incisor and lateral incisor rotated counterclockwise and canine rotated clockwise when the buccal side force was applied.Conclusion: With the increase of the height of the power-arm, the movement pattern of the upper anterior teeth is different. The canine is more sensitive to the height of the power-arm than the central incisor and the lateral incisor. When the height of the power-arm reaches 9mm, the upper anterior teeth are displayed as crown tipping buccally movement. Compare with lingual side force, the buccal side force do better in preventing the loss of anterior tooth torque. If the upper anterior teeth are up-right or lingually tipped before treatment, it is preferable to use longer power-arm or buccal side traction force. If the anterior teeth are already tipped buccally, then short power-arm or lingual side force is advised.Keywords: lingual orthodontic, height of power-arm, movement pattern, 3-D finite element analysis, anterior teeth, maxillary dentition

The bacterial flagellar motor, a remarkable rotary machine, can rapidly switch between counterclockwise (CCW) and clockwise (CW) rotational directions to control the migration behavior of the bacterial cell. The flagellar motor consists of a bi-directional spinning rotor surrounded by torque-generating stator units. Recent high-resolution in vitro and in situ structural studies have revealed stunning details of the individual components of the flagellar motor and their interactions in both the CCW and CW senses. In this review, we discuss these structures and their implications for understanding the molecular mechanisms underlying flagellar rotation and switching.

Purpose: To describe the pattern of the nerves in the inferocentral whorl region of the human corneal subbasal nerve plexus (SBNP) in health and diseases known to affect the subbasal nerves. Methods: Laser-scanning in vivo confocal microscopy (IVCM) was used to image the SBNP bilaterally in 91 healthy subjects, 39 subjects with type 2 diabetes mellitus (T2DM), and 43 subjects with Parkinsons disease (PD). Whorl regions were classified according to nerve orientation relative to age and health/disease status. Results: Of 346 examined eyes, 300 (86.7%) had an identifiable whorl pattern. In healthy subjects, a clockwise nerve orientation of the whorl was most common (67.9%), followed by non-rotatory or seam morphology (21.4%), and counterclockwise (10.7%). The clockwise orientation was more prevalent in healthy subjects than in T2DM or PD (P < 0.001). Healthy individuals below 50 years of age had a predominantly clockwise orientation (93.8%) which was reduced to 51.9% in those over 50 years (P < 0.001). Age but not disease status explained whorl orientation in T2DM and PD groups. Moreover, whorl orientation is bilaterally clockwise in the young, but adopts other orientations and becomes asymmetric across eyes with age. Finally, we report reflective dot-like features confined to the whorl region of the subbasal plexus, sometimes appearing in close association with subbasal nerves and present in 84-93% of examined eyes regardless of disease status, eye or sex. Conclusion: Subbasal nerves in the inferocentral whorl region are predominantly clockwise in young, healthy corneas. With aging and conditions of T2DM and PD, counterclockwise and non-rotatory configurations increase in prevalence, and bilateral symmetry is lost. Mechanisms regulating these changes warrant further investigation. Funding Agencies|Hofgrens fond, NEURO Sweden

The possibility of a major earthquake like 2015 Gorkha–Nepal or even greater is anticipated in the Garhwal–Kumaun region in the Central Seismic Gap of the NW Himalaya. The interseismic strain-rate from GPS derived crustal velocities show multifaceted strain-rate pattern in the region and are classified into four different strain-rate zones. Besides compressional, we identified two NE–SW orienting low strain rate (~ 20 nstrain/a) zones; namely, the Ramganga-Baijro and the Nainital-Almora, where large earthquakes can occur. These zones have surface locking widths of ~ 72 and ~ 75 km respectively from the Frontal to the Outer Lesser Himalaya, where no significant surface rupture and associated large earthquakes were observed for the last 100 years. However, strain reducing extensional deformation zone that appears sandwiched between the low strain-rate zones pose uncertainties on the occurences of large earthquakes in the locked zone. Nevertheless, such zone acts as a conduit to transfer strain from the compressional zone (> 100 nstrain/a) to the deforming frontal active fault systems. We also observed a curvilinear surface strain-rate pattern in the Chamoli cluster and explained how asymmetric crustal accommodation processes at the northwest and the southeast edges of the Almora Klippe, cause clockwise rotational couple on the upper crust moving over the MHT.

In the hinterlands of the Taklimakan Desert, we monitored Barchan dune evolution with the Huace X90 GNSS in RTK working mode to obtain 3D coordinates of a dune with millimeter precision. Using these coordinates, a 3D digital model of the dune was built and superimposed with CASS 9.0 and ArcGIS 10.0. Auto CAD 2010 was used to draw an arc with the three elements of starting point, end point and included angle and to fit the corresponding characteristic point trajectory curve of the eight selected typical dunes. Results of the fitting showed that the dunes rotated counterclockwise with ranges of 33°∼38°and 25.5°∼30° in the monitoring intervals between stages one and two and stages three and four, respectively. The moving trajectories were curves pointing from NE to SW and convex to NW, with long lengths. Between stages two and three, the dunes rotated clockwise with a range of 31°∼37°, and the trajectories was curves pointing from NE to SW and convex to SE or SW, with varying direction and a short length. When the northward or southward angle between effective sand-driving wind and the axial direction was larger than 30°, the dune rotated clockwise or counterclockwise, respectively. This indicates that the moving trajectory should be a curve rather than a straight line, which would result in a better fit with the actual movement of the dune. Accurately fitting the moving trajectory of Barchan dunes can assist in learning how to fit the movement of other mobile dunes as well as how to correct raw dune evolution data, such as moving distance and speed. It can also lay a foundation for the improvement of a formula for moving speed, which is important because many fields of research concern the moving speed and direction of mobile dunes.

Rock excavation has experienced complex stress paths. The development of the original crack under the path of principal stress magnitude and principal stress direction is a key scientific problem that needs to be solved in rock underground engineering. The principal stress magnitude dominates the initiation and propagation of the crack and increases rock damage under the action of principal stress rotation. In this study, the theoretical calculation and numerical analysis method have been combined with the crack propagation conditions to study the stress-driven mechanism of brittle rock crack propagation under principal stress rotation. The results show that the “relative initial angle” of crack angle is being updated in time during the principal stress rotation process; once the stress is rotated, it will become the next initial crack angle; the crack propagation direction is deviated under the applied shear load, and it is always in the direction of minimum shear load, leading to a certain degree of inhibition of crack propagation depth in the initial direction. According to the results of numerical simulation, the effect of principal stress rotation caused by mining excavation is obvious and has a certain range of influence depth, the stress of surrounding rock of roadway is the highest within the depth range of 1∼2 m, and the maximum principal stress is as high as 26.89 MPa. The rotation of principal stress direction on the roadway surrounding rock surface is the strongest, which makes the surrounding rock more fragmented, and the middle principal stress and the maximum principal stress rotate about 90° counterclockwise along the Ox axis. Studying the action mechanism of principal stress rotation on fractured rock masses can provide scientific basis for geotechnical engineering design and rock mass surrounding support.

SUMMARY The 26 May 2019 MW 8.0 Peru intraslab earthquake ruptured the subducting Nazca Plate where the dip angle of the slab increases sharply and the strike angle rotates clockwise from the epicentre to north. To obtain a detailed seismic source model of the 2019 Peru earthquake, including not only the rupture evolution but also the spatiotemporal distribution of focal mechanisms, we performed comprehensive seismic waveform analyses using both a newly developed flexible finite-fault teleseismic waveform inversion method and a back-projection method. The source model revealed a complex rupture process involving a back-propagating rupture. The initial rupture propagated downdip from the hypocentre, then unilaterally northward along the strike of the slab. Following a large slip occurring ∼50–100 km north of the hypocentre, the rupture propagated bilaterally both further northward and back southward. The spatial distribution of focal mechanisms shows that the direction of T-axis azimuth gradually rotated clockwise from the epicentre northward, corresponding to the clockwise rotation of the strike of the subducting Nazca Plate, and the large-slip area corresponds to the high-curvature area of the slab iso-depth lines. Our results show that the complex rupture process, including the focal-mechanism transition, of the Peru earthquake was related to the slab geometry of the subducting Nazca Plate.

Reconstructing the history of Philippine Sea (PHS) plate motion is important for better understanding of the tectonics of the surrounding plates. It is generally considered that the PHS plate migrated northward since Eocene, but its rotation has not been constrained well; some reconstructions incorporated a large clockwise rotation but others did not. This is mainly because the difficulty of collecting oriented rocks from the mostly submerged PHS plate hindered establishing an apparent polar wander path. In this study, we conducted a paleomagnetic study of oriented cores taken using an ROV-based coring apparatus from the Hyuga Seamount on the northern part of the Kyushu-Palau Ridge, a remnant arc in the stable interior of the PHS plate. Stepwise thermal and alternating-field demagnetizations were applied to specimens taken successively from two ~ 30 cm long limestone cores of middle to late Oligocene age, and characteristic remanent magnetization directions could be isolated. Declination and inclination of D = 51.5° and I = 39.8°, respectively, were obtained as the mean of the two cores. The easterly-deflected declination means ~ 50° clockwise rotation of the PHS plate since middle to late Oligocene. In addition, ~ 5° latitudinal change of the site is estimated from the mean inclination. The result implies that the Kyushu-Palau Ridge was located to the southwest of the present position in middle to late Oligocene, and that PHS plate rotation as well as the Shikoku and Parece Vela Basin spreading contributed to the eastward migration of the Izu-Ogasawara (Bonin) Arc to the current position.

Eastward transport and clockwise rotation of crust around the southeastern margin of the Tibetan Plateau dominates active deformation east of the Eastern Himalayan Syntaxis. Current crustal movement inferred from GPS measurements indicates ongoing distortion of the traces of the active Red River fault and the Mesozoic Yalong-Yulong-Longmen Shan thrust belt. By extrapolating current rates back in time, we infer that this pattern of deformation developed since 10.1 ± 1.5 Ma. This date of initiation is approximately synchronous with a suite of tectonic phenomena, both near and far, within the wide Eurasia/Indian collision zone, including the initiation of slip on the Ganzi-Yushu-Xianshuihe fault and crustal thinning and E-W extension by normal faulting on N-S–trending rifts in the plateau interior. Accordingly, the eastward movement of eastern Tibet and the clockwise rotation of that material seem to be local manifestations of a larger geodynamic event at ca. 10–15 Ma that changed the kinematic style and reorganized deformation not only on the plateau-wide scale, but across the entire region affected by the India/Eurasia collision. Convective removal of some or all of Tibet's mantle lithosphere seems to offer the simplest mechanism for these approximately simultaneous changes.

A coherent perception of spatial orientation is key in maintaining postural control. To achieve this the brain must access sensory inputs encoding both the body and the head position and integrate them with incoming visual information. Here we isolated the contribution of proprioception to verticality perception and further investigated whether changing the body position without moving the head can modulate visual dependence—the extent to which an individual relies on visual cues for spatial orientation. Spatial orientation was measured in ten healthy individuals [6 female; 25–47 years (SD 7.8 years)] using a virtual reality based subjective visual vertical (SVV) task. Individuals aligned an arrow to their perceived gravitational vertical, initially against a static black background (10 trials), and then in other conditions with clockwise and counterclockwise background rotations (each 10 trials). In all conditions, subjects were seated first in the upright position, then with trunk tilted 20° to the right, followed by 20° to the left while the head was always aligned vertically. The SVV error was modulated by the trunk position, and it was greater when the trunk was tilted to the left compared to right or upright trunk positions (p p

Background Midface skeletal changes through aging have been conceptualized as a clockwise rotation relative to the cranial base. This finding is mainly supported by cross-sectional population studies based on comparisons between groups of individuals in different age ranges. Few papers have evaluated the intra-individual evolution of the facial skeleton, and those that have included only a limited number of patients. Objectives The authors sought to analyze the intra-individual evolution of the facial skeleton. Methods We conducted a retrospective study including patients who underwent 2 separate facial computed tomography scans (T1 and T2) with a minimum gap of 7 years. Employing 3-dimensional reconstructions, we measured and compared 7 facial angles (glabellar, orbital, piriform, maxillary, subdental, chin, gonial) and 6 facial distances (lacrimal crest, orbital floor, piriform, zygoma, labiomental, gnathion) on both computed tomography scans. Results A total of 56 patients (29 males and 27 females) were included. Mean ages at T1 and T2 were 50 and 59 y, respectively. We found a significant decrease between T1 and T2 in facial angles at the midface (glabella, orbital, piriform, and maxillary angles, all P < 0.0001). We found a significant increase in all facial distances between T1 and T2 for the overall population and for men (all P < 0.05). For women, all distances increased, but only piriform and zygoma distances showed significant changes (P < 0.001 and P < 0.04, respectively). Bone remodeling appeared earlier in women. Conclusions Our study confirms the clockwise rotation of the midface during aging. This finding could lead to a better understanding of aesthetic medicine practices.

The present-day Global Positioning System (GPS) velocity field shows that the Indian Plate is not a complete rigid block, as its northeastern corner has been torn off and clockwise rotating relative to the main part. With the updated GPS velocity data, the Euler vector of the northeastern corner of the Indian Plate relative to the stable main plate is deduced as (89.566 ± 0.06° E, 26.131 ± 0.05° N, 1.34 ± 0.11°/Myr). The peak area of the present-day crustal deformation is located in the Chayu deformation belt with the compressional dilation strain rate over 160 nanostrain/yr. However, the Namche-Barwa Syntaxis with the massive crustal thickening and intense surface erosion is generally considered to be the previous locus of the strongest compressional stress in the Eastern Himalayan Syntaxis over long geological timescales. Thus, there is a discrepancy between the previous and present-day crustal deformation peak areas. We argue the migration of the crustal deformation peak area with a total distance of about 120 km and ascribe it to the variation of stress conditions caused by northeast India's clockwise rotation.

We investigated the primary mechanisms triggering the S-wave splitting (SWS) of seven unusually deep local earthquakes (between 50 and 60 km) which originated in the lithosphere beneath the Rwenzori region. We attempted to develop an understanding of the relationship between anisotropic structures in the lithosphere and tectonic deformation processes. A total of 12 out of 44 waveforms showed evidence of SWS on their polarization diagrams. The fast-wave direction (φ) and delay-time (δt) were estimated using the covariance matrix and the cross-correlation coefficient methods, respectively. We observed a clockwise rotation of φ-directions (NW - SE and ~ENE - WSW) at stations located in the rift valley. We related this pattern of φ-directions to anisotropic fabric, probably lattice-preferred orientation of preexisting olivine, whose a-axes are aligned with ESE absolute plate motion (APM) vector. At stations located outside the rift valley, however, we observed WNW - ESE and NNW - SSE patterns of φ-directions. We associated these patterns to the shape-preferred orientation of structures frozen in the lithosphere that are aligned with the present-day APM direction. We observed δt values ranging between 0.04 ± 0.01s and 0.43 ± 0.02 s, which decrease with distance away from the rift axis. This further supported our concept that the anisotropy observed at stations located on the moving plate is related to aligned melt inclusions frozen in the surrounding lithosphere. We further observed that the δt values increase linearly with ray-path length, which could indicate a fairly uniform anisotropy between 50-km and 60-km depth. Our study reported no evidence of multi-layer anisotropy beneath the Rwenzori region.

Background. External fixation devices (EFD) have found wide application in pelvic fractures treating, but it is not always that strength characteristics of these devices make it possible to realize early rehabilitation. Objective. the biomechanical justification for external pelvic osteosynthesis with use of rods having different thread hands on the basis of analysis of the stress-strain state (SSS) of the “EFD – pelvis” system and an experimental study of the strength of threaded connections of different rods and the pelvic bone under the effect of alternate cyclic loads. Materials and Methods. Was analyzed the SSS of the “EFD – pelvis” system verified in an experimental study of the strength of threaded connections of different rods and the pelvic bone under the effect of alternate cyclic loads. Results. Standing on a single basis in the AVF rods with the same thread, there are torques directed in different directions: on the right - clockwise (screwing in), on the left - counterclockwise (screwing out).A change in the thread direction does not lead to change in the moment values, but directions of the action of the moments of force for the left rod will correspond to the direction of its screwing both in the left- and right-sided one-support position. Conclusions. Bar-connected rods with a differently directed thread create a reciprocally interlocking structure, which counteracts self-unscrewing. Such a structure significantly increases the strength of connection of an EFD with the pelvic bone and creates conditions for an effective use of the early rehabilitation of patients with pelvic fractures.

Human steady-state locomotion modes are symmetrical, leading to symmetric mechanical function of human feet in general; however, track distance running in a counterclockwise direction exposes the runner’s feet to asymmetrical stress. This may induce asymmetrical adaptation in the runners’ foot arch functions, but this has not been experimentally tested. Here, we show that the plantar fascia (PF), a primary structure of the foot arch elasticity, is stiffer for the left than the right foot as a characteristic of runners, via a cross-sectional study on 10 track distance runners and 10 untrained individuals. Shear wave velocity (index of tissue stiffness: SWV) and thickness of PF and foot dimensions were compared between sides and groups. Runners showed higher PF SWV in their left (9.4 ± 1.0 m/s) than right (8.9 ± 0.9 m/s) feet, whereas untrained individuals showed no bilateral differences (8.5 ± 1.5 m/s and 8.6 ± 1.7 m/s, respectively). Additionally, runners showed higher left to right (L/R) ratio of PF SWV than untrained men (105.1% and 97.7%, respectively). PF thickness and foot dimensions were not significantly different between sides or groups. These results demonstrate stiffer PF in the left feet of runners, which may reflect adaptation to their running-specific training that involves asymmetrical mechanical loading.

Left ventricular (LV) twist is calculated from the net difference of counterclockwise apical and clockwise basal rotation during systole. The current study was designed to evaluate correlations between autonomic function and LV rotational mechanics in healthy subjects. The present study comprised 18 healthy subjects (mean age: 36±12 years, 12 men). Three-dimensional speckle tracking echocardiography (3DSTE) could be used for non-invasive evaluation of LV rotation and twist. Autonomic function was assessed by means of 5 standard cardiovascular reflex tests. During 3DSTE, basal LV rotation proved to be -3.24±2.02 degree, while apical LV rotation was 9.08±3.04 degree, therefore LV twist was 11.70±6.80 degree. Valsalva test showed significant correlations with LV basal (r=0.529, P=0.019) and apical rotations (r=-0.534, P=0.022), and LV twist (r=-0.467, P=0.044). Heart rate response to deep breathing significantly correlated with LV twist, as well (r=-0.452, P=0.052). The other tests had no any relationship with rotational characteristics. Correlations exist between parasympathetic autonomic function and 3DSTE-derived LV rotation and twist in healthy subjects.

Directional internal rotation in molecular systems, generally controlled by chirality, is known to occur in natural and artificial systems driven by light or fueled chemically, but spontaneous directional molecular rotation is believed to be forbidden. We have designed a molecular rotor, whereby ferrocene and triptycene linked by a methylene bridge provide two rotational degrees of freedom. On the basis of experimental observations, in conjunction with computational data, we show that the two different modes of rotation are strongly coupled and the spatial orientation of the bistable ferrocene moiety controls the barrier to its own rotation about the triptycene axis. It is proposed that the barrier to clockwise 120° rotation across each individual triptycene blade is lower in the M-enantiomer and for counterclockwise 120° rotation, it is lower in its P-counterpart. These findings demonstrate the possibility of locally preferred thermal directional intramolecular rotation for each dynamically interconverting enantiomer.

Background Laparoscopic distal pancreatectomy (LDP) has become the preferred approach for surgical management of left sided pancreas pathology. Our institution previously published its experience with distal pancreatectomies using a clockwise technique with good outcomes. We now reexamine our outcomes across a longer time interval. Methods From August 2008 to November 2020, 364 patients underwent LDP by hepatobiliary surgeons (HA and JS). All procedures were performed using the same clockwise approach, which includes the stepwise slow compression technique. Retrospective descriptive analysis of patient demographic, clinical, operative, and pathologic data was conducted. Results Of the 364 patients who underwent LDP using this technique, clinically significant postoperative pancreatic fistula (POPF) was noted in 26 (7.1%) patients, while major morbidity and mortality were reported in 9.9% and 0.3%, respectively. Hand-assisted method was required for 18 (4.9%) patients and unplanned conversion in 20 (5.5%) patients. In a subset analysis of patients with pancreatic adenocarcinoma (n = 90), POPF was noted in 13 (14.4%), with minor complications occurring in 34.4% and major morbidity in 14.4%. Conclusion LDP with a clockwise approach for dissection, combined with the stepwise slow compression technique results in excellent outcomes, with even lower POPF rates than originally reported. Subset analysis of patients with pancreatic adenocarcinoma shows acceptable perioperative outcomes with this technique.

The clockwise spiral of troughs marking the Martian north polar plateau forms one of the planet’s youngest megastructures. One popular hypothesis posits that the spiral pattern resulted as troughs underwent poleward migration. Here, we show that the troughs are extensively segmented into enclosed depressions (or cells). Many cell interiors display concentric layers that connect pole- and equator-facing slopes, demonstrating in-situ trough erosion. The segmentation patterns indicate a history of gradual trough growth transversely to katabatic wind directions, whereby increases in trough intersections generated their spiral arrangement. The erosional event recorded in the truncated strata and trough segmentation may have supplied up to ~25% of the volume of the mid-latitude icy mantles. Topographically subtle undulations transition into troughs and have distributions that mimic and extend the troughs’ spiraling pattern, indicating that they probably represent buried trough sections. The retention of the spiral pattern in surface and subsurface troughs is consistent with the megastructure’s stabilization before its partial burial. A previously suggested warm paleoclimatic spike indicates that the erosion could have occurred as recently as ~50 Ka. Hence, if the removed ice was redeposited to form the mid-latitude mantles, they could provide a valuable source of near-surface, clean ice for future human exploration.

In the previous article**, data were given on the clockwise rotation of the Tarim Basin at a speed of 0.461° per million years around a virtual axis within the structure. Additional fieldwork and new evidence confirm earlier findings about the asymmetry of the Indo-Asian collision zone. These data are additional arguments in favor of the rotation of the Tarim Basin and lithospheric interactions along the Tarim boundaries. Conclusions are based on detailed geological and geophysical data.

BACKGROUND Little is known regarding how trotting through curves affects locomotion symmetry in Standardbred trotters. OBJECTIVES To investigate differences in objectively measured Standardbred trotter vertical motion symmetry between straight and non-banked, curved sections of oval trotting tracks during exercise warm-up, using a wireless inertial measurement unit (IMU) system. STUDY DESIGN Cross-sectional, observational study. METHODS Sixteen horses were included. Mixed models were used to assess associations between symmetry, track segment (straight vs curve) and stride duration. RESULTS Significant results for forelimb parameters were dependent on interactions between track segments and stride duration. At mean stride duration (0.611 second), during the curved track segment horses showed a lower maximum vertical position of the head after push-off of the outside forelimb (estimate -2.3 mm, P

Objectives This study aims to investigate the effects of the angles created by the Kirschner wires (K-wires), which are applied in the percutaneous fixation of supracondylar humerus fractures with cross K-wire, with the fracture line on fracture stabilization. Patients and methods The study was conducted on distal humerus fracture models. Medial and lateral K-wires were placed in the fracture models. The angle between the fracture line and the K-wire inserted from medial was represented by alpha (α), while the angle between the fracture line and the K-wires inserted from lateral was represented by beta (β). A combination of various angles (30°, 45°, and 60°) was used in each model, where no two models had the same combination of α and β, resulting in nine different wire configurations. The simulation program was used to simulate the effects of forces, which were applied on rotation, flexion and extension directions, on these models. We measured and compared the stress on the wires and the displacement of fractures under different force configurations. Results When the force was applied in the counterclockwise direction, the stresses were 58 megaPascal (MPa) on medial K-wire, 24 MPa on lower lateral K-wire, and 45 MPa on upper lateral K-wire in (45°, 45°) wire configuration. When the force was applied in the clockwise direction, the stresses were 57 MPa on medial K-wire, 23 MPa on lower lateral K-wire, and 45 MPa on upper lateral K-wire in (45°, 45°) wire configuration. In all models, the increased α and β angles were translated into the decreased stress on K-wires at the fracture level and decreased displacement under rotational deforming forces. Despite having generally lower fracture displacement, the increased α and β angles led to variable changes in the stress on K-wires against flexion and extension forces. Conclusion In supracondylar humerus fractures, increasing the insertion angle of both medial and lateral K-wires augments stabilization and reduces displacement, particularly against rotational deforming forces.

Loop-shaped trajectories are commonly observed in the stock-recruitment relationship (SRR). A mechanism that explains why the loops emerge in SRR has been proposed, and the aim of this study was to validate this mechanism using 62 stocks that live in the waters around Japan, the Northwest Atlantic Fisheries Organization area, and elsewhere. We discuss the relationship between the age at maturity and the slope of the regression line adapted for the SRR data. Further, we discuss whether or not the age at maturity determines whether clockwise or anticlockwise loops are dominant. The results were as follows: 1) The slopes of the regression line adapted for the SRR had positive values when the age at maturity was low. As the age at maturity increased, the slopes decreased to zero and then became negative values. As the age at maturity increased even further, the slopes again changed from negative values to zero and then from zero to positive values. 2) Clockwise loops were dominant when the age at maturity was low, and anticlockwise loops were dominant when the age at maturity was high. As the age at maturity increased even more, clockwise loops again became dominant. These findings coincide well with the results presented by Tanaka et al. In the past, a density-dependent effect has been considered to be the main factor driving the fluctuations, but the present results indicated that a different mechanism may control the SRR and the fluctuations in the population.

Observations of non-random distribution of galaxies with opposite spin directions have recently attracted considerable attention. Here, a method for identifying cosine-dependence in a dataset of galaxies annotated by their spin directions is described in the light of different aspects that can impact the statistical analysis of the data. These aspects include the presence of duplicate objects in a dataset, errors in the galaxy annotation process, and non-random distribution of the asymmetry that does not necessarily form a dipole or quadrupole axes. The results show that duplicate objects in the dataset can artificially increase the likelihood of cosine dependence detected in the data, but a very high number of duplicate objects is required to lead to a false detection of an axis. Inaccuracy in galaxy annotations has relatively minor impact on the identification of cosine dependence when the error is randomly distributed between clockwise and counterclockwise galaxies. However, when the error is not random, even a small bias of 1% leads to a statistically significant cosine dependence that peaks at the celestial pole. Experiments with artificial datasets in which the distribution was not random showed strong cosine dependence even when the data did not form a full dipole axis alignment. The analysis when using the unmodified data shows asymmetry profile similar to the profile shown in multiple previous studies using several different telescopes., Comment: Particles, accepted

Pulkhana anticline is located in Tuzhurmatu area, about 50 km SE of Kirkuk city. The study area forms a part of the Zagros Folded Zone which is situated in the unstable shelf of Iraq within the physiographic zone called Foothill Zone (in the middle of Hemrin- Makhul subzone). The north eastern limb of the anticline reaches to 50ᵒ and the dip of the south western limb reaches to 70ᵒ. The core of the structure comprises the rocks of Fat’ha Formation surrounded by rocks of Injana and Mukdadiya Formations, whereas Bai-Hasan Formation forms the slopes of the low hills surrounding the anticline. These Formations range in age from Middle Miocene to Pliocene. More than 761 readings of joint planes were collected from 20 stations within 5 traverses in the study area. The study of joint sets and system was within Injana and Mukhdadiya formations, along traverses with 3-5 stations for each travers track. The results showed the presence of two sets of tension joints (bc, ac) and five sets of shear joints, through defining the maximum stress axis (σ1) and acute angle dividers for these conjugate joints. It was determined that two directions of Paleostress are present in the area, which are NE-SW and NW-SE. The direction of the first major stress (NE-SW) is orthogonal with, or normal to, the fold axis in the study area, which can be considered as a horizontal component which resulted from oblique collision of Arabian and Eurasian Plates. This old compressive stress is the reason behind the formation of the tension joint (ac) and shear joints, where the sets (ac) and system are perpendicular-semi perpendicular to the bedding plane, as they were formed at an early stage of folding. Also, the ) joint was formed in five tectonic stages with different time intervals. Joints formed in different tectonic stages, in the study area, are attributed to oblique collision of Arabian and Eurasian plates and counter clockwise rotation of Arabian plate relative to Eruasian plate.

In this paper, we present the clockwise-algorithm that solves the extension in 𝑘-dimensions of the infamous nine-dot problem, the well known two-dimensional thinking outside the box puzzle. We describe a general strategy that constructively produces minimum length covering trails, for any 𝑘 ∈ N−{0}, solving the NP-complete (3×3×⋯×3)-points problem inside a 3×3×⋯×3 hypercube. In particular, using our algorithm, we explicitly draw different covering trails of minimal length h(𝑘) = (3^𝑘 − 1)/2, for 𝑘 = 3, 4, 5. Furthermore, we conjecture that, for every 𝑘 ≥ 1, it is possible to solve the 3^𝑘-points problem with h(𝑘) lines starting from any of the 3^𝑘 nodes, except from the central one. Finally, we cover 3×3×3 points with a tree of size 12.

Phase diagram modelling and U-Pb monazite ages reveal a clockwise Pressure-Temperature-time metamorphic evolution in the Paranagua Terrane (Ribeira Belt – SE Brazil) and characterized important tec...

It is significant for identifying mass movement patterns to invert horizontal tectonic stresses at different depths underneath Tibet. In recent years, a large number of achievements focusing on two-dimensional tectonic stresses have been obtained from gravity data. However, three-dimensional tectonic stresses in Tibet are still unknown or debatable. Therefore, in the present study an improved method to multilayer horizontal tectonic stresses using gravity observations is developed. The inverted multilayer horizontal tectonic stresses are in agreement with those from previous studies. In addition, rich tectonic structure and development can be revealed from the inverted multilayer horizontal tectonic stresses: (1) the distribution of horizontal tectonic stresses at various depths shows strong correlation with that of the tectonic elements, where major faults and earthquake epicenters are corresponding with stress highs and the stable basins are consistent with stress lows. (2) the mass movement patterns of whole Tibet present clockwise, and the material movement directions in the west and east are approximately south-north and east-west, respectively. (3) in eastern Tibet, the eastward materials caused by the south-north extrusion between Indian and Eurasian plates are divided into two parts by the stable Sichuan Block, one flowing nearly southeast and the other moving almost northeast. The inverted multilayer horizontal tectonic stresses may provide direct evidences for mass movement patterns in Tibet.

Directional deep brain stimulation (dDBS) electrodes allow to steer the electrical field in a specific direction. When implanted with torque, they may rotate for a certain time after implantation. The aim of this study was to evaluate whether and to which degree leads rotate in the first 24 h after implantation using a sheep brain model. dDBS electrodes were implanted in 14 sheep heads and 3D rotational fluoroscopy (3D-RF) scans were acquired to visualize the orientation of the electrode leads. Electrode leads were clockwise rotated just above the burr holes (180° n = 6, 360° n = 6, 2 controls) and 3D-RF scans were again acquired after 3, 6, 13, 17, and 24 h, respectively. One hundred eighty degree rotated electrodes showed an initial rotation of 83.5° (range: 35.4°–128.3°) and a rotation of 114.0° (range: 57°–162°) after 24 h. With 360° torsion, mean initial rotation was 201° (range: 3.3°–321.4°) and mean rotation after 24 h 215.7° (range 31.9°–334.7°), respectively. Direct postoperative imaging may not be accurate for determining the rotation of dDBS electrodes if torque is present.

Joints are among the most widespread geologic structures as they are found in most each exposure of rock. They differ greatly in appearance, dimensions, and arrangement, besides they occur in quite different tectonic environments. This study is important because joints provide evidence on what kind of stress produced them (history of deformation) and also because they change the characteristics of the rocks in which they occur. The Measured data of joints from the studied area which are located in the high folded zone – Northeast of Iraq, were classified according to their relationship with the tectonic axes by projecting them stereographically using Schmidt net in GEOrient ver.9.5.0 software. The joint systems revealed the orientation of the major stress field that caused the area deformation. Two dominant joint systems were found in most stations of the studied area, which are hko>a (first place) and hko>b (second place). The main stress field direction from the joint’s classification is North East – South West which coincides with the opening of the red sea and the collision between Arabian and Iranian tectonic plates. The North West direction (which comes in the second place) it might be due to the rotational movement (counterclockwise) of the Arabian plate in addition to the effect of local stress in the area.

The studied area is a part of the Arabian plate located within the High Folded Zone of the Zagros Fold-Thrust Belt in northeastern Iraq (Kurdistan Region). The Study area deals with the Shakrok Anticlines is located between Safin Mountain and Sork Mountain. These structures are formed during the Alpine Orogeny in Cretaceous-Tertiary period. Generally, the folded structures are trending NW-SE direction which is parallel to the main Zagros Orogenic trends. The exposed stratigraphic succession of the studied area that represented by 4 formations deposited from the Early Cretaceous which are Shiranish, Aqrah, Bekhme and Qamchuqa formations. Shakrok Anticline are asymmetrical, double plunging and verging toward northeast. This establishes that Merawa is a Tertiary continuation part of Cretaceous Shakrok Anticline, but there is a deflection in the direction of the fold axis that affected the Merawa Anticline due to the effect of strike slip fault addition to Lineament. Shakrok Anticline with Cretaceous successions formed due to the effect of Cretaceous and Tertiary folding phases. But Merawa Anticline with Tertiary succession that formed due to the effect of Tertiary folding phases. The high stress and intensity of the major fault on the southwestern limb rotated and overturned Tertiary successions and changed its dip toward NE. The differences in fold geometry, fold axis, axial surface, and curvilinear hinge imply that the structure formed as a result of two folding phases & lateral growth of folds that developed by changing the direction of the compressional tectonic processes due to Alpine Orogene of Zagros. The fold axis of Shakrok Anticline rotated 16o in anticlockwise trend from Merawa to Sork anticlines. Because of anticlockwise rotation of the Arabian plate due to its collision with Iranian and Anatolian plates.

The North China Craton (NCC) is one of the oldest cratons in the world. Currently, the destruction mechanism and geodynamics of the NCC remain controversial. All of the proposed views regarding the issues involve studying the internal density structure of the NCC lithosphere. Gravity field data are among the most important data in regard to investigating the lithospheric density structure, and gravity gradient data and gravity data each possess their own advantages. Given the different observational plane heights between the on-orbit GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) satellite gravity gradient and terrestrial gravity and the effects of the initial density model on the inversion results, sequential inversion of the gravity gradient and gravity are divided into two integrated processes. By using the preconditioned conjugate gradient (PCG) inversion algorithm, the density data are calculated using the preprocessed corrected gravity anomaly data. Then, the newly obtained high-resolution density data are used as the initial density model, which can serve as constraints for the subsequent gravity gradient inversion. Several essential corrections are applied to the four gravity gradient tensors (Txx, Txz, Tyy, Tzz) of the GOCE satellite, after which the corrected gravity gradient anomalies (T′xx, T′xz, T′yy, T′zz) are used as observations. The lithospheric density distribution result within the depth range of 0–180 km in the NCC is obtained. This study clearly illustrates that GOCE data are helpful in understanding the geological settings and tectonic structures in the NCC with regional scale. The inversion results show that in the crust the eastern NCC is affected by lithospheric thinning with obvious local features. In the mantle, the presented obvious negative-density areas are mainly affected by the high-heat-flux environment. In the eastern NCC, the density anomaly in the Bohai Bay area is mostly attributed to the extension of the Tancheng–Lujiang major fault at the eastern boundary. In the western NCC, the crustal density anomaly distribution of the Qilian block is consistent with the northwest–southeast strike of the surface fault belt, whereas such an anomaly distribution experiences a clockwise rotation to a nearly north–south direction upon entering the mantle.

In estuaries, the morphology of inland and offshore areas usually evolves synergistically. This study examines the decadal link between longitudinal changes in morphology of branching channels and movement of the offshore depo-center (where sediment deposition rate is maximum) of the Yangtze River estuary, under intense human interference. Integrated data analysis is provided on morphology, runoff discharge, and ebb partition ratio from 1950 to 2017. Channel-volume reductions and change rates between isobaths in branching channels reflect the impact of estuarine engineering projects. Ebb partition ratio and duration of discharge ≥ 60 000 m3 s-1 act as proxies for the water excavating force in branching channels and runoff intensity. It is found that deposition occurs in the lower/upper sub-reaches (or further downstream/upstream channels) of the inland north/south branching channels, and the offshore depo-center moves southward or southeastward, as runoff intensity grows; the reverse occurs as runoff intensity declines. This is because the horizontal circumfluence in the Yangtze estuary rotates clockwise as ebb partition ratios of the north/south branching channels increase/decrease for increasing runoff, and conversely rotates anticlockwise for decreasing runoff. Land reclamation activities, the Deepwater Channel Project, and the Qingcaosha Reservoir have impacted greatly on longitudinal changes of morphology in the North Branch and the South Passage and on ebb partition ratio variations in the North/South Channel and the North/South Passage. Dam-induced runoff flattening has enhanced deposition in the upper/lower sub-reaches of the north/south branching channels and caused northward movement of the offshore depo-center, except in areas affected by estuarine engineering projects. Dam-induced longitudinal evolution of branching channel morphology and offshore depo-center movement will likely persist in the future, given the ongoing construction of large cascade dams in the upper Yangtze and the completion of major projects in the Yangtze estuary.

Previous observations of a large number of galaxies show differences between the photometry of spiral galaxies with clockwise spin patterns and spiral galaxies with counterclockwise spin patterns. In this study the mean magnitude of a large number of clockwise galaxies is compared to the mean magnitude of a large number of counterclockwise galaxies. The observed difference between clockwise and counterclockwise spiral galaxies imaged by the space-based COSMOS survey is compared to the differences between clockwise and counterclockwise galaxies imaged by the Earth-based SDSS and Pan-STARRS around the same field. The annotation of clockwise and counterclockwise galaxies is a fully automatic process that does not involve human intervention, and in all experiments both clockwise and counterclockwise galaxies are separated from the same fields. The comparison shows that the same asymmetry was identified by all three telescopes, providing strong evidence that the rotation direction of a spiral galaxy is linked to its luminosity as measured from Earth. Analysis of the luminosity difference using a large number of galaxies from different parts of the sky shows that the difference between clockwise and counterclockwise galaxies changes with the direction of observation, and oriented around an axis., Comment: Open Astronomy, accepted

The ability of digital sky surveys to collect and store very large amounts of data provides completely new ways to study the local universe. Perhaps one of the most provocative observations reported with such tools is the asymmetry between galaxies with clockwise and counterclockwise spin patterns. Here I use $\sim1.7\cdot10^5$ spiral galaxies from SDSS and sort them by their spin patterns (clockwise or counterclockwise) to identify and profile a possible large-scale pattern of the distribution of galaxy spin patterns as observed from Earth. The analysis shows asymmetry between the number of clockwise and counterclockwise spiral galaxies imaged by SDSS, and a dipole axis. These findings largely agree with previous reports using smaller datasets. The probability of the differences between the number of galaxies to occur by chance is (P, AN, accepted

Restudy of an Ordovician diploporite specimen from the Middle Ordovician of central Spain reveals that the species ‘Calix’ inornatus MELÉNDEZ has four ambulacra, each with two equal facets, an oval hydropore and a smooth thecal surface. In contrast, the type species of Calix has four ambulacra, each with four facets added in a clockwise direction during growth, a trilobed hydropore, and a theca with spiny plates. Other aristocystitid genera with four ambulacra have one facet per ambulacrum. ‘Calix’ inornatus differs from all other aristocystitid genera and warrants a new generic name, for which we propose Enodicalix.

The Caspian Sea is the largest enclosed basin on Earth and a unique subject for the analysis of tidal dynamics. Tides in the basin are produced directly by the tide-generating forces. Using the Princeton Ocean Model (POM), we examine details of the spatial and temporal features of the tidal dynamics in the Caspian Sea. We present tidal charts of the amplitudes and phase lags of the major tidal constituents, together with maps of the form factor, tidal range, and tidal current speed. Semi-diurnal tides in the Caspian Sea are determined by a Taylor amphidromic system with anticlockwise rotation. The largest M2 amplitude is 6 cm and is located in Türkmen Aylagy (called Turkmen Bay hereafter). For the diurnal constituents, the Absheron Peninsula separates two individual amphidromes with anticlockwise rotation in the north and in the south. The maximum K1 amplitudes (up to 0.7–0.8 cm) are located in (1) the south-eastern part of the basin, (2) Türkmenbaşy Gulf, (3) Mangyshlak Bay; and (4) Kizlyar Bay. As a result, the semi-diurnal tides prevail over diurnal tides in the Caspian Sea. The maximum tidal range, of up to 21 cm, has been found in Turkmen Bay. The strongest tidal currents have been located in the straits to the north and south of Ogurja Ada, where speeds reach 22 and 19 cm s−1, respectively. Numerical simulations of the tides using different mean sea levels (within a range of 5 m) indicate that spatial features of the Caspian Sea tides are strongly sensitive to changes in mean sea level.

Background The side-bridge (SB) is a commonly used closed-chain task to assess trunk muscle endurance and side-to-side endurance asymmetry. An open-chain variation of the SB, that positions the participant in an inclined side-lying posture, may be useful for those who report shoulder pain or fatigue as the reason for terminating the closed-chain SB. Low back loading demands of the open- and closed-chain variations should be matched to facilitate comparison of SB endurance measures. Purpose To quantify the low back reaction moments during the open- and closed-chain SB and determine the appropriate open-chain angle of inclination that matches the lateral bend moment magnitude of the closed-chain SB. Study Design Observational cohort. Methods Upper body and trunk postural data were obtained during the closed-chain SB and during the open-chain SB at each of four inclination angles from a group of eight healthy male adults. Ground reaction force (GRF) data were also collected during the closed-chain SB. Low back reaction moments were calculated using a static 'top-down' linked segment model in both SB variations. Latent growth modeling was used to determine the angle of inclination in the open-chain SB that produced a low back lateral bend moment that matched the closed-chain SB. Sensitivity of the matching open-chain inclination angle was evaluated by rotating the measured GRF vector from the closed-chain SB by five degrees clockwise and counter-clockwise in the frontal plane. Results The open-chain inclination angle that best matched the loading demands of the closed-chain SB was 38 ± 12 degrees. Clockwise rotation of the measured GRF in the closed-chain SB increased the matching inclination angle to 56 ± 17 degrees. Counter-clockwise rotation reduced the matching inclination angle to 17 ± 11 degrees. Secondary descriptive analysis of spine posture and off-axis low back moments revealed biomechanically relevant differences between SB positions. Conclusion The average open-chain SB angle of inclination that matched the closed-chain SB approximated the 45-degree recommendation offered in the literature. Differences in spine posture and off-axis low back reaction moments, and the potential impact on holding times, should be considered if using the open-chain SB. Level of Evidence 2b.