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[Abstract Normal faults grow either by radial propagation and segment linkage or by accruing displacement without a proportional increase in fault length. To test these competing models of fault growth, a novel 2D seismic stratigraphic interpretation of the recent Fucino Basin of the central Apennines (Italy) has been performed. The Fucino is a major Pliocene‐Quaternary non‐marine ‘extensional collapse basins’, developed immediately after the Apenninic compressional strain had locally abated, and bounded by seismogenic faults that generate strong (Mw = 6–7) and destructive earthquakes. The Fucino is an overall dual polarity half‐graben, built around two border fault systems: the northern one lies along the east‐northeast striking Avezzano‐Bussi regional fault‐zone; the other, south‐eastern trending, bounds the basin to the east. Two separate fault‐driven depocentres of fluvio‐lacustrine sequences (maximum thicknesses of ~1,750 m) are present. One is associated to the northern border faults, with mainly Late Pliocene activity; the second is to the hanging‐wall of the eastern border‐faults and reveals a stepwise Pleistocene‐Recent activity. Tectonic depocentres have migrated clockwise through time, and new‐born fault systems have developed at the south‐eastern basin periphery (Gioia dei Marsi area). This, together with the progressive accumulation of throw in time without significant fault lengthening, suggests that the model of fault growth by segment linkage is not the best explanation for this basin. Instead, the stepwise onset and growth of the Fucino extensional collapse faulting, and its ongoing earthquake hazard, may have been promoted by polyphase inversion tectonics of inherited deep‐seated zones of weaknesses (e.g. Avezzano‐Bussi Line)., The Fucino is an overall dual polarity half‐graben, built around two border fault systems: the northern one lies along the east‐northeast striking Avezzano‐Bussi regional fault‐zone; the other, south‐eastern trending, bounds the basin to the east. Two separate fault‐driven depocentres of fluvio‐lacustrine sequences (maximum thicknesses of ~1,750 m) are present. The northern border fault showed mainly a Late Pliocene activity; the eastern border‐faults reveal a stepwise Pleistocene‐Recent activity. Tectonic depocentres have migrated clockwise through time, and new‐born fault systems have developed at the south‐eastern basin periphery (Gioia dei Marsi area). This, together with the progressive accumulation of throw in time without significant fault lengthening, suggests that the model of fault growth by segment linkage is not the best explanation for this basin. ]

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

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.

Sediment fingerprinting has been widely used to distinguish discrete sediment sources; however, application to intra‐storm sediment source variability has received relatively little focus despite the benefit being long recognized. In this investigation, sediment fingerprinting was applied to a 53‐hr storm event sampled hourly to determine sediment source dynamics throughout the event. Sediment sources were differentiated using 16 variables, and source contribution determined using Bayesian and Frequentist mixing models for comparison. Both models provided comparable source predictions for the dominant source estimates and the general temporal pattern. The Frequentist model appeared to exhibit some unreliable values coinciding with low GOF and attributed to inherent model structure. The Bayesian model showed higher uncertainty, likely due to the “process error” utilized associated with single sample mixtures. High variability in sediment source contribution was observed between hourly time steps; however, local smoothing reveals temporal trends during the event. A higher average proportion of mudstone is found in the falling limb (0.544) compared with the rising limb (0.464), and the reverse is observed for mountain range (0.218 vs. 0.283) and unconsolidated (0.073 vs. 0.055). In the initial hours of the storm, mudstone source contribution significantly drops, whereas mountain range and unconsolidated contributions peak. The SSC‐Q clockwise hysteresis indicates proximal sediment sources, suggesting the mudstone sediment is stored channel sediment and easily entrained. This sediment flushes through, coinciding with a drop as the distal mountain range and unconsolidated sources arrive to peak contribution. The wider Manawatū discharge and sediment load then arrive, delivering increasing levels of mudstone throughout the remainder of the event while mountain range sediment diminishes. Spatial representation of the sediment source contribution was derived from distributing sediment source loads to the spatial extent of the source material according to sub‐catchment sediment loads and was weighted according to slope. This provided an effective means to visualize the origin of the sediment and a better spatial interpretation of sediment fingerprinting results, which is typically limited by poor spatial resolution.

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

BACKGROUND Configurational changes in the proximal aorta are relevant to the procedural difficulty of transcatheter aortic valve implantation (TAVI). Among several morphological changes involving the ascending aorta, elongation is characteristics of elderly patients with aortic stenosis and can compromise the success and safety of TAVI. However, the effect of ascending aortic elongation on the overall morphology of the proximal aorta has not been established. AIMS Our primary purpose was to investigate the effect of ascending aortic elongation on structural changes in the proximal aorta in TAVI candidates. MATERIALS & METHODS In total, 121 consecutive patients with severe aortic stenosis (mean age, 84.5 ± 5.3 years; 69% women) who had undergone preprocedural computed tomography before TAVI were enrolled. We examined the structural anatomy of the proximal aorta in detail, focusing on its elongation, dilatation, tilting, rotation, and wedging. RESULTS The mean length of the ascending aorta was 68.0 ± 9.2 mm, and the length was significantly correlated with dilatation (R = .278, p = .002), rightward tilting (R = .437, p

Objectives To evaluate the diagnostic accuracy of ultrasound (US) to diagnose the directionality of testicular rotation and the degree of spermatic cord twist in pediatric patients with testicular torsion. Methods A retrospective review of 14 pediatric patients with testicular torsion was conducted. The directionality of testicular rotation was classified as an inner or outer direction (inner, counterclockwise in the left testis [viewed from below] and clockwise in the right testis; and outer, counterclockwise in the right testis and clockwise in the left testis). The Clopper-Pearson method and the Fisher exact, Mann-Whitney U, and Wilcoxon signed rank sum tests were used for the statistical analyses. Results The diagnostic accuracy of US in the directionality of testicular rotation and the degree of spermatic cord twist were 78.6% (11 of 14; 95% confidence interval, 49.2%-95.3%) and 36.4% (4 of 11; 95% confidence interval, 10.9%-69.2%), respectively. Outer rotation was seen in 50.0% of the cases. The directionality of testicular rotation and the degree of spermatic cord twist as determined by US were not significantly different between the patients with salvaged testis and those with testicular loss (inner/outer direction, 4/2 versus 4/4; P = .627; mean twist ± SD, 330.0° ± 73.5° versus 337.5° ± 115.4°; P > .999). There was no significant difference in the degree of spermatic cord twist determined by US and surgical results (343.0° ± 97.1° versus 458.2° ± 168.2°; P = .063). Conclusions The accuracy of US in determining the directionality of testicular rotation was relatively high in our small cohort. This information may be useful for pediatric surgeons and urologists when performing early manual reduction for testicular torsion.

The Chenghai fault zone, an important part of the Dali fault system, is instrumental in comprehending the crustal deformation of the southeastern margin of the Tibetan Plateau. Detailed remote sens...

[This study suggests that the Bohai Bay Basin is a composite extensional‐transtensional basin and that the counter‐clockwise rotation in the direction of Pacific Plate subduction drove the clockwise rotation of the basin velocity field. , Abstract A well‐constrained plate deformation model may lead to an improved understanding of sedimentary basin formation and the connection between subduction history and over‐riding plate deformation. Building quantitative models of basin kinematics and deformation remains challenging often due to the lack of comprehensive constraints. The Bohai Bay Basin (BBB) is an important manifestation of the destruction of the North China Craton, and records the plate kinematic history of East Asia during the Cenozoic. Although a number of interpretations of the formation of the BBB have been proposed, few quantitative basin reconstruction models have been built to test and refine previous ideas. Here, we developed a quantitative deformation reconstruction of the BBB constrained with balanced cross‐sections and structural, stratigraphic and depositional age data. Our reconstruction suggests that the basin formation process was composed of three main stages: Paleocene‐early Eocene (65–42 Ma) extension initiation, middle Eocene‐early Oligocene (42–32.8 Ma) extension climax and post‐Oligocene (32.8–0 Ma) post‐extensional subsidence. The deformation of the BBB is spatially heterogeneous, and its velocity directions rotated clockwise during the basin formation process. The reconstruction supports the interpretation that the BBB formed via strike‐slip faulting and orthogonal extension and that the basin is classified as a composite extensional‐transtensional basin. We argue that the clockwise rotation of the basin velocity field was driven by the counter‐clockwise rotation in the direction of Pacific Plate subduction. The kinematics of the BBB imply that the Pacific Plate may have been sufficiently coupled to the over‐riding East Asian Plate during the critical period of Pacific Plate reorganization. The new reconstruction provides a quantitative basis for studies of deformation processes not only in the vicinity of the BBB, but also more broadly throughout East Asia.]

Crustal material eastward extrusion from the Tibetan Plateau is closely related to the strike-slip faults in the SE margin of the Tibetan Plateau. The left-lateral strike-slip Xianshuihe–Xiaojiang ...

Modern sand transport pathways in a multiple-sand-ridge system are elusive and have rarely been studied in recent years. We report herein a field with four en echelon linear sand ridges offshore of Hainan Island in the Beibu Gulf and describe the distribution and morphology of these sand ridges in detail for the first time. Dune crest comparisons and seismic profiles are also interpreted to assess sand transport over the dunes. Based on a Delft 3D model, regional tidal currents and tide-induced bedload transport in the multiple-sand-ridge system were simulated to provide insights into the related bedload transport paths. The results show that bedload transport and residual flows are mostly directed to the south on the east side of the sand ridges and to the north on the west side, and these differences coincide with dune asymmetries and migrations. Cross-ridge transport is weak and mostly converges on the crests of sand ridges from the two flanks. The bedload transport is unbalanced on either flank of the sand ridges, thus leading to the asymmetry and crest kinks of the sand ridges. A distinct correlation is not observed between the net cross-ridge sand transport and sand ridge asymmetry. In this system, cross-swale transport is significant between the neighboring sand ridges and helps construct the bedload transport circulation in the swales. Sand accretion also occurs in the swales and benefits from the southwestward bedload transport from the north end of sand ridge 3. Distinct evidence has not been found for closed bedload transport circulation around sand ridges in this multiple-sand-ridge system, although limited clockwise current vortices develop on several sand ridges. Additional field observations and simulations are required to characterize the suspended load transport in a multiple-sand-ridge system, and the effects of local sand supply conditions on sand transport also need further evaluation. Copyright (c) 2018 John Wiley & Sons, Ltd.

The misfit dislocations at α-Fe2 O3 /α-Al2 O3 heterostructure interfaces were investigated by high-resolution transmission electron microscopy (HRTEM), geometric phase analysis (GPA) and dislocation density tensor analysis. When imaged along the [112¯0] direction, the misfit dislocation core is a mixed-type, which can be characterised by one extra (11¯02) plane and one extra (1¯104) plane of α-Al2 O3 . Dislocation density tensor analysis gave a very high accuracy in determining the corresponding Burgers vectors of two extra half-planes. By comparing the measured Burgers vectors with theoretical ones, we are able to determine local rotations in the dislocation core region: the (11¯02) plane is rotated clockwise 6.25° and the (1¯104) plane is rotated anticlockwise 4.81°. Such a local rotation is favourable from the viewpoint of both energy and function to relax lattice misfit.

While observing a specific traffic sign in the field, we noticed an apparent distortion of size and shape of the circle that contained the sign. This novel illusion manifests as a distortion of the horizontal compared to the vertical dimension of the sign. The illusion seems to be underlined by similar mechanisms to those in the Delboeuf illusion. The aim of our study was to determine the existence and magnitude of the snow tire illusion. We conducted two experiments using the method of constant stimuli. The first experiment was conducted on the standard sign, while in the second, the stimuli were rotated 90° counterclockwise. Both experiments consisted of three conditions: the snow tire, the ellipse, and the simple circle (control) conditions. The data showed a robust illusion effect for both the standard and rotated sign compared to the control condition, with a large majority of participants experiencing the illusion. The snow tire illusion seems to be a combination of assimilation mechanisms of different magnitudes. The assimilation is larger for one dimension of the sign, thus producing the shape distortion. The illusion may be a manifestation of a thus far undocumented non-uniform effect of assimilation on perceived size and shape.

This study places new constraints on the pressure-temperature (P–T) path and duration of high-temperature (HT) metamorphism recorded by Archean granulite-facies metasedimentary rocks from the northern Wyoming Province in the eastern Beartooth Mountains, MT and WY, USA. These rocks exist as m- to km-scale xenoliths within a c. 2.8 Ga calc-alkaline granitoid batholith. Different interpretations of the timing of HT metamorphism relative to batholith intrusion in previous works has led to ambiguity over the mechanism by which these rocks were heated (i.e. batholith intrusion vs. a later, cryptic event). The P–T path recorded by these rocks and the duration of this path may be indicative of the heating mechanism but are not currently well constrained. Here we combine phase equilibria thermobarometry and diffusion modelling of major element zonation in garnet in order to constrain the P–T path of HT metamorphism and the durations of different parts of this path. It is shown that these rocks record a tight, clockwise P–T path characterized by near-isobaric heating at ~6.5-7 kbar to ˜770-800 °C, HT decompression to ~6 kbar, 780-800 °C, followed by limited decompression while cooling. Diffusion modelling of major element zonation in garnet suggests that HT decompression was brief (likely

The Central Yunnan Plateau (CYP) is located in the southeastern end of the Sichuan-Yunnan rhombic block. CYP is surrounded by the South China Block to the east and the Indo-China Block to the southwest. Stratigraphy and topography research shows the relative surface uplift of the CYP since the Pliocene. However, the widely accepted model of lower crustal flow is very difficult to fully explain the surface uplift of CYP, with faults and fold structures in the brittle shallow crust. The lower crust thickening led by the lower crustal flow only contributes 34–54% (600–950 m) of the total surface uplift. The wide-angle seismic profiles and topography analysis show that the CYP surface uplift is predominately a consequence of isostatic compensation due to surface erosion, upper-middle crustal shortening, and lower crustal thickening. The average isostatic adjustment caused by surface erosion of CYP is about 500 m, which is about 29% of the total surface uplift (1750 m). The GPS station velocities, focal mechanisms, and seismic anisotropy show the strong decoupling relationship between upper-middle crust and lower crust. In detail, there is a movement with southeast-directed and clockwise rotation around the Eastern Himalayan syntaxis in the upper-middle crust, although south-directed flow in the lower crust. The southeast motion of the upper-middle crust could be resolved into two portions. The eastward component of upper-middle crust motion is obstructed by the South China Block in the east. The result is the W-E direction shortening of upper-middle crust, shown by the S-N trending CYP anticlinorium. The W-E direction shortening of upper-middle crust contributes 17–37% (300–650 m) of the total surface uplift. In contrast, the southward component of upper-middle crust motion, shown by the sinistral strike-slip displacement of the Xiaojiang fault zone, could pass through the Red River fault zone into the Indo-China Block, where the left-lateral Dien Bien Phu Fault would be the counterpart. The contribution of upper-middle crustal shortening in a S-N direction is very limited. The lower crustal flow could have been playing a prominent role in the growth of the whole southeast margin of the Tibetan Plateau, and the contribution from upper-middle crustal shortening cannot be ignored in some local areas.

The synoptic characteristics and statistical variability of seasonal dust over southwestern Saudi Arabia are studied for the period from 1979 to 2006 using the aerosol index (AI) from the Total Ozone Mapping Spectrometer (TOMS) satellite, dust observations from surface stations, and meteorological data from the National Center for Environmental Prediction and the National Center for Atmospheric Research (NCEP/NCAR) reanalysis data set. The seasonal AI distribution indicates that approximately 80% of each year was dusty and that most of the dust occurred during hot months. In addition, the surface observations of the dust types show that the stations with the largest number of dust observations throughout the year were close to the desert, except during the summer, when the stations near the Red Sea had the largest number of dust observations. The synoptic forces that influenced the dust cases were the relative positions of high-pressure systems (Azores or Siberian) and low-pressure systems (Sudan or Indian), alongside their interactions. The relative positions of the atmospheric systems are highly pronounced at a pressure level of 850 hPa; at this pressure, the systems are oriented from north (anticyclonic system) to south (cyclonic system), turn anticlockwise to become oriented from west (anticyclonic system) to east (cyclonic system) during the summer, and then turn clockwise during the winter. Moreover, the interaction of the atmospheric systems influences the wind pattern of the seasonal composition over the southern Arabian Peninsula, which produces an anticyclonic wind pattern during winter, a cyclonic wind pattern during spring, a northerly/northwesterly wind pattern during summer and an anticyclonic wind pattern during autumn. The dust sources changed because of the relative positions of these atmospheric systems, in which the ‘Toker Gap’ Sudan was the summer/autumn dust source, and the ‘central and eastern’ Arabian Peninsula was the winter/spring dust source.

Aim To evaluate oval root canal preparation using one or two instruments in counterclockwise or clockwise reciprocating motion. Methodology The radiographic diameter of mandibular human incisors was evaluated, and oval canals were selected (2 ≤ Diameter Ratio ≤ 4). Fifty-seven teeth were assigned to root canal preparation (n = 19): Reciproc 40 (R40) in a counterclockwise reciprocating motion; Mtwo size 40, .06 taper (M 40.06) in a clockwise reciprocating motion or Mtwo size 20, .06 taper and size 40, .06 taper (M 20/40.06) in a clockwise reciprocating motion. Mtwo instruments were coupled to an ENDO DUAL motor, turning 150° clockwise and 30° counterclockwise. Scanning was performed before and after root canal preparation using a SkyScan 1176 micro-computed tomography. Volume, percentage of debris and percentage of uninstrumented surface were analysed in the entire root canal and in each third of the canal. Data were compared using anova and Tukey's tests or Kruskal–Wallis and Dunn tests. Results The Reciproc and Mtwo systems using different kinematics were associated with a similar increase in root canal volume. Additionally, both system had similar percentage of uninstrumented surface (P > 0.05). Mtwo size 20, .06 taper and size 40, .06 taper was associated with significantly lower debris (P

We examined interdecadal variations in potential fishing grounds for the Pacific saury, Cololabis saira, off the southeastern coast of Hokkaido, Japan, for the early fishing season of August–September. We applied linear trend analysis to a time series of several oceanographic variables for 1993–2014. Trends in the appearance frequency of sea surface temperatures (SST) of 12–18 °C during August–September indicated an interdecadal reduction in the potential fishing area off the Hokkaido coast. There were localized significant increases of both SST and the sea level anomaly along the Kuril–Kamchatka Trench off the Hokkaido coast. The localized trends coincided with decadal decreases of satellite-based chlorophyll concentrations after 2002. Analysis of mesoscale eddies revealed that the localized trends were related to clockwise (counterclockwise) eddies that appeared more frequently (less frequently) near the trench in recent years. Moreover, the Oyashio transport on the slope between the coast and the trench decreased significantly and completely disappeared in some recent summers. Interactions between the Oyashio and mesoscale eddies resulted in an interdecadal shift in the cold-water intrusion along the main stream of the Oyashio from the along-slope direction to the offshore direction in the upstream region of the Hokkaido coast, and large areas of favorable potential fishing grounds near the Hokkaido coast have disappeared in recent years.

Objectives/Hypothesis During intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery, endotracheal (ET) tube migration can result in a decrease in vocalis electromyographic (EMG) amplitude without a concordant latency elevation during stimulation of the recurrent laryngeal nerve (RLN). Study Design Retrospective review. Methods Data were reviewed retrospectively for thyroid and parathyroid surgery patients with IONM of the laryngeal nerves from January 2015 to December 2015. Recordings of vocalis EMG amplitudes and latencies with RLN stimulation were obtained with the neuromonitoring ET tube surface electrodes in optimal baseline position, with vertical displacement away from the vocalis, and with rotational change away from baseline. Results ET tube surface electrode EMG recordings were obtained with stimulation of seven left and three right RLNs in a total of 10 patients. Mean vocalis EMG amplitudes were reduced with vertical displacement 1 and 2 cm both inferior and superior to baseline and with rotational change (45° and 90° clockwise and counterclockwise, 180°), although amplitude change with 45° clockwise and 180° rotation did not meet statistical significance. Mean EMG latency values did not change significantly from baseline with either rotation or vertical displacement of the ET tube. Conclusions An isolated decrease in EMG amplitude without concordant latency elevation should warrant re-evaluation of ET tube position during thyroid and parathyroid surgery and is in contrast to a combined event, with both EMG amplitude decrease and concordant latency increase, which is more suggestive of a true neuropraxic injury. Level of Evidence 4. Laryngoscope, 127:2182–2188, 2017

Foliation inflexion/intersection axes (FIAs) preserved within porphyroblasts that grew throughout Isan orogenesis reveal significant anticlockwise changes in the direction of bulk horizontal shortening between 1670 and 1500 Ma from NE–SW, N–S, E–W to NW–SE. This implies an anticlockwise shift in relative plate motion with time during the Isan orogeny. Dating monazite grains amongst the axial planar foliations defining three of the four FIAs enabled an age for the periods of relative plate motion that produced these structures to be determined. Averaging the ages from monazite grains defining each FIA set revealed 1649±12 Ma for NE–SW shortening, 1645±7 Ma for N–S shortening, and 1591±10 Ma for that directed E-W. Inclusion trail asymmetries indicate shear senses of top to the SW for NW–SE FIAs and dominantly top to the N for E–W FIAs, reflecting thrusting towards the SW and N. No evidence for tectonism related to early NE–SW bulk horizontal shortening has previously been detected in the Mount Isa Inlier. Amalgamation of the Broken Hill and possibly the Gawler provinces with the Mount Isa province may have taken place during these periods of NE–SW and N–S-directed thrusting as the ages of tectonism are similar. Overlapping dates, tectonic, metamorphic, and metallogenic similarities between eastern Australia (Mount Isa and Broken Hill terranes) and the southwest part of Laurentia imply a most probable connection between both continental masses. Putting Australia in such position with respect to North America during the Late-Paleo-to-Mesoproterozoic time is consistent with the AUSWUS model of the Rodinia supercontinent.

Current understanding of bedform dynamics is largely based on field and laboratory observations of bedforms in steady flow environments. There are relatively few investigations of bedforms in flows dominated by unsteadiness associated with rapidly changing flows or tides. As a consequence, the ability to predict bedform response to variable flow is rudimentary. Using high-resolution multibeam bathymetric data, this study explores the dynamics of a dune field developed by tidally modulated, fluvially dominated flow in the Fraser River Estuary, British Columbia, Canada. The dunes were dominantly low lee angle features characteristic of large, deep river channels. Data were collected over a field ca 1·0 km long and 0·5 km wide through a complete diurnal tidal cycle during the rising limb of the hydrograph immediately prior to peak freshet, yielding the most comprehensive characterization of low-angle dunes ever reported. The data show that bedform height and lee angle slope respond to variable flow by declining as the tide ebbs, then increasing as the tide rises and the flow velocities decrease. Bedform lengths do not appear to respond to the changes in velocity caused by the tides. Changes in the bedform height and lee angle have a counterclockwise hysteresis with mean flow velocity, indicating that changes in the bedform geometry lag changes in the flow. The data reveal that lee angle slope responds directly to suspended sediment concentration, supporting previous speculation that low-angle dune morphology is maintained by erosion of the dune stoss and crest at high flow, and deposition of that material in the dune trough.

Background Current guidelines recommend the routine use of tricuspid annular plane systolic excursion (TAPSE) as a simple method for estimating right ventricular (RV) function. However, when ventricular apical longitudinal rotation (apical-LR) occurs in pulmonary hypertension (PH) patients, it may result in overestimated TAPSE. Methods We studied 105 patients with PH defined as mean pulmonary artery pressure >25 mmHg at rest measured by right heart cardiac catheterization. TAPSE was defined as the maximum displacement during systole in the RV-focused apical four-chamber view. RV free-wall longitudinal speckle tracking strain (RV-free) was calculated by averaging 3 regional peak systolic strains. The apical-LR was measured at the peak rotation in the apical region including both left and right ventricle. The eccentricity index (EI) was defined as the ratio of the length of 2 perpendicular minor-axis diameters, one of which bisected and was perpendicular to the interventricular septum, and was obtained at end-systole (EI-sys) and end-diastole (EI-dia). Twenty age-, gender-, and left ventricular ejection fraction-matched normal controls were studied for comparison. Results The apical-LR in PH patients was significantly lower than that in normal controls (−3.4 ± 2.7° vs. −1.3 ± 1.9°, P = 0.001). Simple linear regression analysis showed that gender, TAPSE, EI-sys, and EI-dia/EI-sys were associated with apical-LR, but RV-free was not. Multiple regression analysis demonstrated that gender, EI-dia/EI-sys, and TAPSE were independent determinants of apical-LR. Conclusions TAPSE may be overestimated in PH patients with clockwise rotation resulting from left ventricular compression. TAPSE should thus be evaluated carefully in PH patients with marked apical rotation.

Structured Abstract Objectives To investigate how displacements of maxillo-mandibular structures are associated with each other at splint removal and 1 year post-surgery following 1-jaw and 2-jaw surgeries for correction of Class III malocclusion. Setting and Sample Population Fifty patients who underwent surgical correction with maxillary advancement only (n = 25) or combined with mandibular setback (n = 25) were prospectively enrolled in this study. Methods Cone-beam computed tomographies were taken pre-surgery, at splint removal and at 1 year post-surgery. Three-dimensional cranial base superimpositions and shape correspondence were used to measure the outcomes from pre-surgery to splint removal (surgical changes) and splint removal to 1 year post-surgery (post-surgical adaptations). Pearson's correlation coefficients were used to evaluate the association between the regional displacements. Results Both surgery groups presented mandibular clockwise rotation with surgery and post-surgical adaptive counterclockwise rotation. In patients treated with maxillary advancement only, the surgical changes of the maxilla were significantly correlated with chin changes. The amount and direction of chin autorotation were significantly correlated with right and left ramus autorotation. Right and left condylar displacements were significantly correlated. One year post-surgery, adaptive displacements and bone remodeling of both rami were correlated with the chin and condylar changes. For the 2-jaw group, the few correlations between the positional and remodeling changes in the anatomic regions of interest observed due to the surgery were different than those observed after post-surgical adaptations, suggesting that these changes occurred independently. Conclusion Our results indicate that surgical displacements and post-surgical adaptations are often correlated in one-jaw surgery and are, in general, independent in two-jaw surgery.

This study investigates the relationship between the wind wave climate and the main climate modes of atmospheric variability in the North Atlantic Ocean. The modes considered are the North Atlantic Oscillation (NAO), the East Atlantic (EA) pattern, the East Atlantic Western Russian (EA/WR) pattern and the Scandinavian (SCAN) pattern. The wave dataset consists of buoys records, remote sensing altimetry observations and a numerical hindcast providing significant wave height (SWH), mean wave period (MWP) and mean wave direction (MWD) for the period 1989–2009. After evaluating the reliability of the hindcast, we focus on the impact of each mode on seasonal wave parameters and on the relative importance of wind-sea and swell components. Results demonstrate that the NAO and EA patterns are the most relevant, whereas EA/WR and SCAN patterns have a weaker impact on the North Atlantic wave climate variability. During their positive phases, both NAO and EA patterns are related to winter SWH at a rate that reaches 1 m per unit index along the Scottish coast (NAO) and Iberian coast (EA) patterns. In terms of winter MWD, the two modes induce a counterclockwise shift of up to 65° per negative NAO (positive EA) unit over west European coasts. They also increase the winter MWP in the North Sea and in the Bay of Biscay (up to 1 s per unit NAO) and along the western coasts of Europe and North Africa (1 s per unit EA). The impact of winter EA pattern on all wave parameters is mostly caused through the swell wave component.

It is well known that a counterclockwise rotation occurred in the Miocene in northeast Japan. However, the detailed timing and mechanism of the rotation has been debated. Moreover, there has been no research about the relationship between rotational tectonics and the evolution of sedimentary basins. We carried out paleomagnetic and rock magnetic analyses in Nishiwaga Town, Iwate Prefecture, northeast Japan, where the stratigraphy and sedimentary basin formation have previously been clarified. We found that there was a counterclockwise rotational movement of about 45° at about 15 Ma. From our results and previous studies on the tectonics and sedimentary basin development, we are able to ascertain the following tectonic history and sedimentary basin evolution in this area: (i) before the rotational movement, sandstone and mudstone were deposited in a tranquil environment with no volcanic activity coupled with slow tectonic subsidence; (ii) between 16.4–15.1 Ma and 14 Ma, a counterclockwise rotation occurred with rapid tectonic subsidence and continuous explosive volcanism; (iii) at about 14 Ma, the counterclockwise rotation ended and there was a reduction in both subsidence and volcanism. This result shows the impact that rotational tectonics can have on sedimentary basin formation.

Garnet crystallization in metapelites from the Barrovian garnet and staurolite zones of the Lesser Himalayan Belt in Sikkim is modelled utilizing Gibbs free energy minimization, multi-component diffusion theory and a simple nucleation and growth algorithm. The predicted mineral assemblages and garnet-growth zoning match observations remarkably well for relatively tight, clockwise metamorphic P–T paths that are characterized by prograde gradients of ∼30 °C kbar−1 for garnet-zone rocks and ∼20 °C kbar−1 for rocks from the staurolite zone. Estimates for peak metamorphic temperature increase up-structure toward the Main Central Thrust. According to our calculations, garnet stopped growing at peak pressures, and protracted heating after peak pressure was absent or insignificant. Almost identical P–T paths for the samples studied and the metamorphic continuity of the Lesser Himalayan Belt support thermo-mechanical models that favour tectonic inversion of a coherent package of Barrovian metamorphic rocks. Time-scales associated with the metamorphism were too short for chemical diffusion to substantially modify garnet-growth zoning in rocks from the garnet and staurolite zones. In general, the pressure of initial garnet growth decreases, and the temperature required for initial garnet growth was reached earlier, for rocks buried closer toward the MCT. Deviations from this overall trend can be explained by variations in bulk-rock chemistry.

Trees on the side directly exposed to sunlight generally grow faster than on the opposite side, a phenomenon termed plant phototropism. There are in situ vertical trunks of silicified wood in the Xiadelongwan area of Yanqing County, north Beijing, where the first National Geologic Park of Petrified Wood of China has been built since 2002. A few trunks have well-preserved growth rings. One petrified stump from the formation shows a positive phototropism direction of SW230°. As compared with the modern normal growth stumps in Beijing plain area, which have a positive phototropism direction of SW210 ° ± 5°, the evidence of wood phototropism supports the conclusion of previous palaeomagnetic studies that the North China Plate has rotated clockwise since the Late Jurassic. The known petrified wood stumps in the Yanshan-Liaoning area are mainly found from the strata of 165–136 Ma, which corresponds to the main stage of the Yanshanian Movement.

Age-related morphological changes of the aorta, including dilatation and elongation, have been reported. However, rotation has not been fully investigated. We focused on the rotation of the ascending aorta and investigated its relationship with tortuosity. One hundred and two consecutive patients who underwent computed tomography coronary angiography were studied. The angle at which the en face view of the volume-rendered image of the right coronary aortic sinus (RCS) was obtained without foreshortening was defined as the rotation index. It was defined as zero if the RCS was squarely visible in the frontal view, positive if it rotated clockwise toward the left anterior oblique (LAO) direction, and negative if it rotated counter-clockwise toward the right anterior oblique (RAO) direction. The tortuosity was evaluated by measuring the biplane tilt angles formed between the ascending aorta and the horizontal line. The mean rotation index, posterior tilt angle viewed from the RAO direction (αRAO), and anterior tilt angle viewed from the LAO direction (αLAO) were 4.8 ± 16.3, 60.7 ± 7.0°, and 63.6 ± 9.0°, respectively. Although no correlation was observed between the rotation index and the αLAO (β = −0.0761, P = 0.1651), there was a significant negative correlation between the rotation index and αRAO (β = −0.1810, P

Forward and inverse mineral equilibria modelling of metapelitic rocks in the hangingwall and footwall of the Plattengneiss, a major shear zone in the Eastern Alps, is used to constrain their tectonometamorphic evolution and assess models for their exhumation. Forward (pseudosection) modelling of two metapelitic rocks suggests a steep clockwise P–T path with a near-isothermal decompression segment from a pressure peak at ~18–19 kbar and 670 °C to the metamorphic peak at 680–720 °C and 11–13 kbar. A subsequent decrease to 600–645 °C and 8–9 kbar is inferred from the late growth of staurolite in some samples. Conventional thermobarometric calculations (inverse modelling) on 18 samples with the inferred peak assemblage garnet + plagioclase + muscovite + biotite + quartz + rutile ± ilmenite ± kyanite are associated with large 2σ uncertainties, and absolute pressures calculated for all samples are statistically indistinguishable. However, calculations constraining relative pressure differences (ΔP) between samples sharing a common mineral assemblage are associated with much smaller uncertainties and yield pressure differences that are statistically meaningful. Although the overall pattern is complicated, the results suggest a pressure gradient of up to 3 kbar across the shear zone that is consistent with volume loss and a model of exhumation related to slab extraction for the Plattengneiss shear zone.

LA–ICP–MS in situ U–Pb monazite geochronology and P–T pseudosections are combined to evaluate the timing and physical conditions of metamorphism in the SE Anmatjira Range in the Aileron Province, central Australia. All samples show age peaks at c. 1580–1555 Ma, with three of five samples showing additional discrete age peaks between c. 1700 and 1630 Ma. P–T phase diagrams calculated for garnet–sillimanite–cordierite–K-feldspar–ilmenite–melt bearing metapelitic rocks have overlapping peak mineral assemblage stability fields at ~870–920 °C and ~6.5–7.2 kbar. P–T modelling of a fine-grained spinel–cordierite–garnet–biotite reaction microstructure suggests retrograde P–T conditions evolved down pressure and temperature to ~3–5.5 kbar and ~610–850 °C. The combined geochronological and P–T results indicate the SE Anmatjira Range underwent high-temperature, low-pressure metamorphism at c. 1580–1555 Ma, and followed an apparently clockwise retrograde path. The high apparent thermal gradient necessary to produce the estimated P–T conditions does not appear to reflect decompression of high-P assemblages, nor is there syn-metamorphic magmatism or structural evidence for extension. Similar to previous workers, we suggest the high-thermal gradient P–T conditions could have been achieved by heating, largely driven by high heat production from older granites in the region.

OBJECTIVES The purpose of this study was to determine the normal value of left ventricular (LV) twist in 3-dimensional (3D) geometry and to study the effects of aging on 3D LV twist by sophisticated newly developed 3D speckle-tracking echocardiographic techniques. METHODS Recent developments in miniaturized ultrasound arrays have provided us with high-quality 3D echocardiographic data. Speckle tracking based on 3D images is robust to out-of-plane motion error, whereas 2-dimensional speckle tracking is inherently unable to analyze 3D cardiac motion and may lead to measurement inaccuracies. Three-dimensional LV volumetric images were acquired from 124 healthy volunteers (aged 21-82 years) and were analyzed by a recent speckle-tracking method. Left ventricular twist was analyzed as apical rotation relative to the base in the 3D coordinates. The measured parameters in this study were peak apical rotation, peak basal rotation, peak LV twist, normalized peak LV twist, and peak untwist velocity. RESULTS As seen from the apex, the normal LV maintains a wringing systolic displacement with an initial counterclockwise rotation followed by a clockwise rotation in the LV basal plane and a counterclockwise rotation in the LV apical plane. In general, the apical and basal twist increases during the aging process, leading to an increased LV twist value. The mean peak twist ± SD in young participants (21-35 years) was 11.73° ± 2.67°, whereas the value for older participants (>65 years) was 18.57° ± 3.08° (P < .001). CONCLUSIONS Three-dimensional speckle-tracking echocardiography can be an effective noninvasive method for assessing 3D LV twist. Age-related differences in the 3D LV twist may be the result of the age-related changes in the endocardial myofibers.

We have conducted a paleomagnetic investigation of the Kozagawa Dike, which is part of the Kumano Acidic Rocks that are the product of a Middle Miocene volcano- plutonic complex cropping out on the Kii Peninsula of Southwest Japan. The granite porphyry facies of the dike yields stable remanent magnetization components. Precisely determined site-mean directions of characteristic components, as revealed by principal component analysis of stepwise alternating-field and thermal demagnetization results, form a tight cluster. The overall mean direction exhibits an approximately 40° clockwise declination shift from the south and a steep negative inclination (D = 217.3°, I =- 59.8°, a95 = 2.8°; 10 sites). Rock magnetic analyses suggest that magnetite is the main stable component carrier. The overall mean direction is interpreted to be a geologically instan- taneous record of the paleomagnetic field that was acquired in a relatively short time interval relative to paleomagnetic secular variations. The mean direction in geographic (in situ) coordinates obtained for the Kozagawa Dike is distinct from previously published data for laccolithic granite porphyry intrusions of the Kumano Acidic Rocks. This differ- ence may result from a time lag during acquisition of remanent magnetization by the different units of the Kumano Acidic Rocks. The southwest and up paleomagnetic direction has previously been interpreted as representing clockwise rotation of Southwest Japan associated with back-arc opening of the Japan Sea. However, we contend that these directions actually reflect the transient capture of an extraordinary paleomagnetic field at ca 14.3 Ma, such as a transitional or excursional state, and are not of tectonic origin.

Over the lasts two decades equal channel angular pressing (ECAP) has been widely used to produce ultrafine grained microstructures with excellent mechanical properties in metallic materials. In this paper, a crystal plasticity finite element method (CPFEM) investigation has been carried out to examine the texture evolution and deformation heterogeneity of copper single crystals deformed by ECAP process. Two single crystals were simulated to examine the influence of initial crystallographic orientation. In the first crystal, the 111‾ slip plane and the 1¯10 slip direction have been rotated by 20° in a clockwise direction around the transverse direction from the theoretical shear plane and theoretical shear direction of the ECAP die, respectively. By contrast in the second crystal, the 111‾ slip plane and the 1¯10 slip direction were rotated 20° in a counter-clockwise direction. The results of the simulation show that the initial crystallographic orientation has a great influence on the deformed geometry, formation of the corner gap, distribution of the plastic strain rate and texture evolution when copper single crystals are undergoing ECAP process. The crystallographic rotation patterns during deformation have been quantitatively estimated and the predicted textures are consistent with the experimental results in the literature.

Background Cavotricuspid isthmus-dependent counterclockwise atrial flutter (typical AFL) is characterized by negative saw-tooth morphology flutter wave (F-wave) in the inferior leads, which is classified as type 1 with purely negative F-wave without positive terminal deflection (PTD), type 2 with small PTD, and type 3 with broad PTD. The determinants of these morphological differences remain to be elucidated. Methods and Results Of 72 patients (58 males, 65 ± 13 years) with typical AFL, 19 were classified as type 1 and 53 as types 2 and 3. We created an electroanatomic map of the right atrium (RA) during AFL and determined which RA site activation corresponded to which F-wave component by analyzing the activation map. It was revealed that F-wave component from the nadir to terminal deflection point coincided with the cranio-caudal activation of the RA free wall (RAFW) in all types. The bipolar voltage map showed that type 1 had the greater extent of low voltage (

A series of reports in the literature indicated symmetry breaking in assemblies of chiral molecules of opposite handedness. These unexpected observations could be accounted for as being generated by the “parity violation” of the nuclear weak force, combined with an autocatalytic amplification process. However, in many such cases, in particular of chiral fluids, this putative mechanism is far from providing a reasonable explanation for such discrimination. In this article it is suggested that space may have deviated a priori from absolute symmetry, a possibility which complies with observations in atoms and molecules and may even be implicated in the asymmetrical configuration of spiral galaxies. Space asymmetry can be extrapolated to a difference between the relative statistical weights of the “right” versus the “left” directions with respect to Euclidian coordinates or, analogously, to a difference between the clockwise and anticlockwise orientations in polar coordinates. The difference in weights of these directions in space is estimated to be around 1%, based on the differences observed in density values of chiral fluids and chiral crystals of NaClO3. The implied asymmetry of time, as the conjugated fourth dimension, suggests a similar difference in magnitude of the time coordinate in a right-handed versus left-handed space, which is feasible for experimental verification. Chirality 25:308–311, 2013. © 2013 Wiley Periodicals, Inc.

We present new Middle Miocene paleomagnetic data for the central Japan Arc, and discuss their implications for Miocene rotation. To obtain a refined paleodirection, we made magnetic measurements on basaltic to andesitic lavas and intrusive rocks from 12 sites in the Tsugu volcanic rocks (ca 15 Ma) in the northern part of the Shitara area, Japan. Significant secondary magnetizations in samples with strong magnetic intensities are interpreted as lightning-induced components. Mean directions carried by magnetite and/or titanomagnetite were determined for all sites. An overall mean direction with a northerly declination was obtained from dual-polarity site means for nine sites. This direction is indistinguishable from the mean direction for coeval parallel dikes in the northern part of the Shitara area, and also indistinguishable from the Miocene reference direction derived from the paleopole for the North China Block in the Asian continent. These comparisons suggest little or no rotation or latitudinal motion in the study area with respect to the North China Block since 15 Ma. We obtained a refined early Middle Miocene paleodirection (D = 9.7°, I = 52.5°, α95 = 4.8°; 30 sites) and paleopole (82.0°N, 230.8°E, A95 = 5.6°) for Shitara by combining data from the Tsugu volcanic rocks and a coeval dike swarm. An anomalous direction found at three sites could be a record of an extraordinary field during a geomagnetic polarity transition or excursion. Paleomagnetic data from Shitara suggest that: (i) the western wing of the Kanto Syntaxis, a prominent cuspate geologic structure in central Honshu, underwent a counterclockwise rotation with respect to the main part of the southwestern Japan Arc between ca 17.5 Ma and 15 Ma; (ii) collision between the Japan and Izu–Bonin (Ogasawara) Arcs began prior to 15 Ma; and (iii) clockwise rotation of the entire southwestern part of the Japan Arc had ceased by 15 Ma.

Directly measured velocity data collected in Lake Superior between 2008 and 2011 show that currents in the open waters of the lake are dominated by near-inertial energy. The near-inertial signal is composed almost entirely of clockwise rotation, with vertical structure dominated by the first baroclinic mode, where waters above and below the thermocline are roughly 180° out of phase with each other. The strength of the oscillations is strongly related to the strength of the stratification; in periods of the year when the water column is well-mixed (typically late autumn and late spring) the near-inertial signal is very weak; when stratification exists, near-inertial oscillations can occur. Combining the velocity amplitudes with an estimate of the thermocline displacement allows estimation of the dominant direction and horizontal wavelength of the near-inertial field, showing that horizontal wavelengths are on the order of 50–100 km, and the direction of the waves veers counter-clockwise over the course of the season with a period of ∼ 1 month. Observations of backscatter suggest that inertial oscillations may be responsible for re-suspension of bottom sediments, which could have significant ecological consequences.

The latest hydraulic fracturing and stress relief measurement data of Chinese mainland were collected and supplemented to “Database of Crustal Stress in China and Adjacent Areas” which was established in 2003. They include 3586 in situ stress data collected at 1474 points. The data are distributed in a space of longitudes 75°E–130°E, latitudes 18°N–47°N, and depths 0~4000 meters covering all active blocks and of north-south seismic belt which are of great importance in tectonic research. Depth-grouping analysis was made in this paper to solve the problem caused by uneven distribution of measurements in the depth range. The magnitude and direction characteristics of stresses measured in the shallow crust of Chinese mainland and each study area were given. The results were summarized as follows. (1) The magnitudes of maximum horizontal stress, minimum horizontal stress and vertical stress all increase linearly with depth. (2) The lateral pressure coefficient values are scattered in superficial and tend to concentrate with increasing depth to be 0.68. At depth of 465 m, dominance turns from horizontal stress to vertical stress. (3) The magnitude of horizontal differential stress is 3MPa on the surface, which grows with depth at a gradient 5.8 MPa/km. (4) In the middle depth range of measurement data in Chinese mainland (depth 2000 m), the descending order of stress magnitudes in blocks is: 63.6 MPa in Qinghai-Tibet, 57.3 MPa in north section of the north-south seismic belt, 51.4 Mpa in South China, 50.5 MPa in North China, 47.9 MPa in middle section of the north-south seismic belt, 47.5 MPa in Northwest China, 45.4 MPa in south section of the north-south seismic belt, and 44.8 MPa in Northeast China. Generally, stresses are high in west and low in east. This indicates that the India-Eurasia collision determines the general pattern of the tectonic stress field in Chinese mainland. (5) Compared other study regions, the northward crustal compression to the Qinghai-Tibet block is relatively lower magnitudes in the shallow subsurface and higher in deep. (6) Radically oriented maximum horizontal stresses characterize the Tibetan Plateau, the directions of which gradually rotated clockwise from N-S to NNE-SSW, NE-SW, NEE-SWW, NW-SE, consistent with focal mechanism solutions.

Constraints from P-T pseudosections (MnNCKFMASH system), foliation intersection/inflection axes preserved in porphyroblasts (FIAs), mineral assemblages and textural relationships for rocks containing all three Al2SiO5 polymorphs indicate a kyanite→ andalusite→ sillimanite sequential formation at different times rather than stable coexistence at the Al2SiO5 triple point. All three Al2SiO5 polymorphs grew in the Chl, Bt, Ms, Grt, St, Pl and Crd bearing Ordovician Clayhole Schist in Balcooma, northeastern Australia separately along a looped P-T-t-D path that swaps from clockwise to anticlockwise in the tectono-metamorphic history of the region. Kyanite grew during crustal thickening in an Early Silurian Orogenic event followed by decompression/heating, andalusite and fibrolitic sillimanite growth during Early Devonian exhumation.

Terra Nova, 24, 339–350, 2012 Abstract Studies of regional plate-scale processes that may influence the exhumation of ultra-high pressure (UHP) metamorphic rocks are few despite their potential importance. Here, we review and summarize available age constraints along with the Qinling-Dabie Shan orogen, which separates the North China Block (NCB) from the South China Block (SCB). We find that collision-related events in the west and extension-related events in the east, where the large Dabie Shan UHP terrane is located, were contemporaneous. Available palaeomagnetic data indicate clockwise rotation of the SCB relative to the NCB during this time. Previous work indicated that the collision propagated from east to west where indentation of the SCB into the Qinling-Dabie Shan orogen was active in the Hannan Dome area at 165 ± 3 Ma as constrained by new 40Ar/39Ar dates on synkinematic sericite in an indentation-related mylonitic shear zone. While this contraction was occurring in the west, exhumation of the UHP terrane was occurring in the Dabie Shan in the east. We propose that the collision of the SCB with the NCB occurred not only in a scissor-like fashion, as previously suggested, but also involved a later rotation about a pole west of the Dabie Shan during the closure of the Mianlue Ocean. As a consequence of this rotation, extension occurred between the South China Block and North China Block east of the pole of rotation leading to extensional exhumation of the Dabie Shan orogen. This microcontinent-scale rotation of the SCB may have provided an important component in the exhumation of the largest UHP terrane in the world.

The aim of this study was to investigate whether cyclic fatigue resistance is increased for nickel titanium instruments manufactured with improved heating processes in clockwise or counterclockwise continuous rotation. The instruments compared were produced either using the R-phase heat treatment (K3XF; SybronEndo, Orange, CA, USA) or the M-wire alloy (ProFile Vortex; DENTSPLY Tulsa Dental Specialties, Tulsa, OK, USA). Tests were performed with a specific cyclic fatigue device that evaluated cycles to failure of rotary instruments in curved artificial canals. Results indicated no significant difference in resistance to cyclic fatigue when rotary nickel titanium instruments are used in clockwise or counterclockwise continuous rotation. In both directions of rotation, size 04-25 K3XF showed a significant increase (P

The use of reciprocating motion for a nickel-titanium file has been claimed to increase its resistance to fatigue in comparison to continuous rotation. The purpose of this study was to investigate the effect using a reciprocating motion instead of continuous rotation for nickel-titanium files on their cyclic fatigue resistance. Cyclic fatigue tests simulating clinical use with ProTaper F2 and ProFile #25/.06 instruments were carried out in an artificial stainless-steel root canal with a 1.5 mm inner diameter, 5 mm radius and 60° angle of curvature. The instruments were driven using either continuous rotation or reciprocation until fracture. For the reciprocation, the rotation angles were set to 140° clockwise and 45° counterclockwise. The number of cycles to fracture was determined by measuring the time to fracture. Statistical analysis was performed using two-way anova. There were no significant differences in the fracture cycles due to the use of reciprocation or continuous rotation for either instrument. The results found using reciprocation were comparable to those found using continuous rotation with regard to the cyclic fatigue resistance of nickel-titanium rotary files.

Gambarini G, Gergi R, Naaman A, Osta N, Al Sudani D. Cyclic fatigue analysis of twisted file rotary NiTi instruments used in reciprocating motion. International Endodontic Journal, 45, 802–806, 2012. Abstract Aim To evaluate the cyclic fatigue fracture resistance of engine-driven twisted file (TF) instruments under reciprocating movement. Methodology A sample of 30 size 25, 0.08 taper NiTi TF instruments was tested in a simulated canal with 60˚ angle of curvature and a 3 mm radius. During mechanical testing, different movement kinematics were used at a constant speed, which resulted in three experimental groups (each group n = 10). The instruments from the first group (G1) were rotated until fracture occurred. The instruments in the second (G2) and third group (G3) were driven under reciprocating movement with different angles of reciprocation. The time of fracture for each instrument was measured, and statistical analysis was performed using one-way analysis of variance followed by Tukey’s Honestly Significant Different test. Results Reciprocating movement resulted in a significantly longer cyclic fatigue life (P