Translational Axes Research Articles

The eIF3a translational control axis in the Wnt/β-catenin signaling pathway and colon tumorigenesis

Translational initiation in protein synthesis is an important regulatory step in gene expression and its dysregulation may result in diseases such as cancer. Translational control by eIF4E/4E-BP has been well studied and contributes to mTOR signaling in various biological processes. Here, we report a novel translational control axis in the Wnt/β-catenin signaling pathway in colon tumorigenesis by eIF3a, a Yin-Yang factor in tumorigenesis and prognosis. We show that eIF3a expression is upregulated in human colon cancer tissues, pre-cancerous adenoma polyps, and associates with β-catenin level and APC mutation in human samples, and that eIF3a overexpression transforms intestinal epithelial cells. We also show that eIF3a expression is regulated by the Wnt/β-catenin signaling pathway with an active TCF/LEF binding site in its promoter and that eIF3a knockdown inhibits APC mutation-induced spontaneous colon tumorigenesis in APCmin/+ mice. Together, we conclude that eIF3a upregulation in colon cancer is due to APC mutation and it participates in colon tumorigenesis by adding a translational control axis in Wnt/β-catenin signaling pathway and that it can serve as a potential target for colon cancer intervention.

Simulation of Motion Nonlinear Error Compensation of CNC Machine Tools With Multi-Axis Linkage

In order to solve the problem of nonlinear error for a dual rotary table five-axis CNC machine tool due to the linkage of rotary and translational axes, the simulation of motion nonlinear error compensation for a multi-axis linkage CNC machine tool is proposed. The adjacent points in the tool position file are selected as the tool position points for building the model, and then the nonlinear error model resolved by the harmonic function is established according to the error distribution in the classical post-processing. The nonlinear error between the two tool position points is quickly predicted by the analytical expression of this model, and the real-time error compensation of the intermediate interpolation points is realized. Finally, MALTLAB simulation analysis is performed on the tool position file of an impeller part machining to verify the effectiveness of the proposed algorithm. The experimental results show that it can be seen from the distribution curve of the nonlinear error that it is about 10% after compensation as before compensation, thus verifying the effectiveness of the nonlinear error compensation mechanism. The correctness of the nonlinear error analysis and compensation method and the effectiveness of post-processing are verified.

Defective regulation of the eIF2-eIF2B translational axis underlies depressive-like behavior in mice and correlates with major depressive disorder in humans

Major depressive disorder (MDD) is a significant cause of disability in adults worldwide. However, the underlying causes and mechanisms of MDD are not fully understood, and many patients are refractory to available therapeutic options. Impaired control of brain mRNA translation underlies several neurodevelopmental and neurodegenerative conditions, including autism spectrum disorders and Alzheimer’s disease (AD). Nonetheless, a potential role for mechanisms associated with impaired translational control in depressive-like behavior remains elusive. A key pathway controlling translation initiation relies on the phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α-P) which, in turn, blocks the guanine exchange factor activity of eIF2B, thereby reducing global translation rates. Here we report that the expression of EIF2B5 (which codes for eIF2Bε, the catalytic subunit of eIF2B) is reduced in postmortem MDD prefrontal cortex from two distinct human cohorts and in the frontal cortex of social isolation-induced depressive-like behavior model mice. Further, pharmacological treatment with anisomycin or with salubrinal, an inhibitor of the eIF2α phosphatase GADD34, induces depressive-like behavior in adult C57BL/6J mice. Salubrinal-induced depressive-like behavior is blocked by ISRIB, a compound that directly activates eIF2B regardless of the phosphorylation status of eIF2α, suggesting that increased eIF2α-P promotes depressive-like states. Taken together, our results suggest that impaired eIF2-associated translational control may participate in the pathophysiology of MDD, and underscore eIF2-eIF2B translational axis as a potential target for the development of novel approaches for MDD and related mood disorders.

Research on the Magnetorheological Finishing Technology of a High-Steepness Optical Element Based on the Virtual-Axis and Spiral Scanning Path.

Magnetorheological finishing (MRF) of aspherical optical elements usually requires the coordination between the translational axes and the oscillating axes of the machine tool to realize the processing. For aspheric optical elements whose steepness exceeds the machining stroke of the equipment, there is still no better method to achieve high-precision and high-efficiency error convergence. To solve this problem, an MRF method combining virtual-axis technology and a spiral scanning path is proposed in this paper. Firstly, the distribution law of the magnetic induction intensity inside the polishing wheel is analyzed by simulation, the stability of the removal efficiency of the removal function within the ±7∘ angle of the normal angle of the polishing wheel is determined, and MRF is expanded from traditional single-point processing to circular arc segment processing. Secondly, the spiral scanning path is proposed for aspherical rotational symmetric optical elements, which can reduce the requirements of the number of machine tool axes and the dynamic performance of machine tools. Finally, an aspherical fused silica optical element with a curvature radius of 400 mm, K value of -1, and aperture of 100 mm is processed. The PV value of this optical element converges from 189.2 nm to 24.85 nm, and the RMS value converges from 24.85 nm to 5.74 nm. The experimental results show that the proposed combined process has the ability to modify curved optical elements and can be applied to ultra-precision machining of high-steepness optical elements.

Mechanical behavior of unsaturated soils from suction controlled ring shear tests

The shear strength behavior associated with a large shear deformation of both the fine- and coarse-grained unsaturated soils is important in interpreting and forecasting the initiation and movement of landslides. For this reason, a suction-controlled ring shear apparatus was designed by introducing modifications to the conventional Bromhead ring apparatus extending the axis translation technique. A series of suction-controlled ring shear tests were performed on fine- and coarse-grained unsaturated soil specimens subjecting to large shear deformation. The experimental results are presented and interpreted for highlighting: (i) the shear stress/void ratio-shear displacement relationships; (ii) the envelopes of the residual shear strength; (iii) the void ratio, water ratio and degree of saturation of the fine-grained soil specimens sheared to the residual state under different net normal stresses and matric suctions. These results provide valuable information toward understanding and interpreting the behaviors of landslides in unsaturated soils that experience the first failure and the reactivation along a pre-sheared slip surface.

Two-photon polymerization-based fabrication of millimeter-sized precision Fresnel optics

Two-photon polymerization (2PP) is known to be the most precise and highest resolution additive manufacturing process for printing optics, but its applicability is restricted to a few applications due to the limited size of printable objects and low throughput. The presented work is intended to demonstrate the performance of printing millimeter-scale optics by implementing appropriate stitching methods into a setup that combines a Galvo scanner and translational axes. In this work, specifically, Fresnel axicons with a diameter of 3.5 mm are manufactured by 2PP to substantiate the applicability of the process. Manufacturing Fresnel optics instead of volumetric optics allows for attaining acceptable process times with durations of tens of hours highlighting the appeal of 2PP for rapid prototyping in optics. The suitability of the Fresnel axicons for beam shaping is confirmed through illumination with a laser beam. The resulting ring-shaped intensity distribution in the far field behind the Fresnel axicon is captured using a beam profiler. Furthermore, the influence of different stitching parameters on the resulting intensity distribution is investigated. The experimental results are validated by simulations, where the intensity distribution in the far field behind an axicon was calculated by Fourier transformation. Simulations were carried out to discuss the effect of manufacturing errors on the far field intensity distribution.

Knowledge Management in the COVID-19 Era

The pandemic has been a watershed in the knowledge management that is carried out in Higher Education Institutions (HEIs). Studies on vulnerability and resilience risks highlight material, financial and human resources as the central axis of the knowledge network, although research on stigma indicates that mistrust prevails between decision makers and those who carry them out. Therefore, the objective of this work was to contrast the hypotheses related to knowledge management as a regulatory process of trust relationships between the parties involved. A cross-sectional, exploratory, and correlational study was carried out with a sample of 10 professional practitioners and social workers involved in COVID-19 care. The results show that a structure of nodes prevails that begins with innovation, continues with competitiveness and ends with efficiency as central, unifying and structural axes of information translation and knowledge transfer. The results are not extensive to the university community, although they are innovative because they highlight trust as the guiding principle of knowledge management.

Knowledge Management in the Literature From 2021 to 2024

The COVID-19 pandemic has significantly impacted knowledge management in Higher Education Institutions (HEIs). Studies have found that material, financial, and human resources are the key factors in the knowledge network, and mistrust often exists between decision-makers and those who carry out the work. This study aimed to investigate the relationship between knowledge management and trust by conducting a cross-sectional, exploratory, and correlational study with a sample of 10 professional practitioners and social workers involved in COVID-19 care. The study findings show that innovation, competitiveness, and efficiency are the central, unifying, and structural axes of information translation and knowledge transfer. These results are not extensive to the university community, and they are innovative because they highlight the importance of trust as the guiding principle of knowledge management.

Critical state behaviour of an unsaturated kaolin mixture

In this paper, a series of suction-controlled triaxial tests were conducted to investigate the hydromechanical behaviour of an unsaturated kaolin mixture. The studied variables included the mean net stress, suction, and initial dry density. The suction was controlled over a wide range – in the span of 0–390 MPa using the axis translation method and the vapour equilibrium technique, aiming to holistically study the mechanical response of unsaturated soils. The discussion focused on the critical state behaviour and dilatancy characteristics of the tested soil. The experimental results indicate that the ductility of the soil decreases and shifts towards brittleness with increasing suctions. The critical state stress ratio (Ma) of the soil exhibits a significant increase with suction, and this increase becomes more pronounced with higher initial dry density. Conversely, the impact of suction on the critical state line in the specific volume-mean net stress plane (v-lnpnet plane) diminishes with higher initial dry density. Furthermore, suction notably influences the stress-dilatancy relationship of kaolin mixtures, while the effect of confining pressure appears to be marginal. The influence of suction on the stress-dilatancy relationship primarily stems from its impact on the critical stress ratio (Ma), which can be normalized by dividing the stress ratio by the critical state stress ratio. Lastly, the stress-dilatancy equation of the modified Cam-clay model is extended to capture the effect of suction on the dilatancy characteristics of unsaturated soils.

Modeling, detection, and validation for geometric errors in machine tools

Abstract This study aims to enhance the spatial precision of five-axis machining centers through a comprehensive exploration of geometric errors, encompassing modeling, efficient detection, and compensation validation. Our approach begins with the establishment of a kinematic error model covering XYZ translational axes and AC rotational axes, providing an in-depth understanding of error origins and interrelationships. Utilizing a laser tracker, we conduct direct measurements of the geometric errors associated with translational axes, and a rotational axis error detection model is developed by using a ball bar, allowing for indirect analysis of rotational axis geometric errors. The validity of both the kinematic error model and error detection is further confirmed through practical on-machine measurements.

Implementation of MIMO Radar-Based Point Cloud Images for Environmental Recognition of Unmanned Vehicles and Its Application

High-performance radar systems are becoming increasingly popular for accurately detecting obstacles in front of unmanned vehicles in fog, snow, rain, night and other scenarios. The use of these systems is gradually expanding, such as indicating empty space and environment detection rather than just detecting and tracking the moving targets. In this paper, based on our high-resolution radar system, a three-dimensional point cloud image algorithm is developed and implemented. An axis translation and compensation algorithm is applied to minimize the point spreading caused by the different mounting positions and the alignment error of the Global Navigation Satellite System (GNSS) and radar. After applying the algorithm, a point cloud image for a corner reflector target and a parked vehicle is created to directly compare the improved results. A recently developed radar system is mounted on the vehicle and it collects data through actual road driving. Based on this, a three-dimensional point cloud image including an axis translation and compensation algorithm is created. As a results, not only the curbstones of the road but also street trees and walls are well represented. In addition, this point cloud image is made to overlap and align with an open source web browser (QtWeb)-based navigation map image to implement the imaging algorithm and thus determine the location of the vehicle. This application algorithm can be very useful for positioning unmanned vehicles in urban area where GNSS signals cannot be received due to a large number of buildings. Furthermore, sensor fusion, in which a three-dimensional point cloud radar image appears on the camera image, is also implemented. The position alignment of the sensors is realized through intrinsic and extrinsic parameter optimization. This high-performance radar application algorithm is expected to work well for unmanned ground or aerial vehicle route planning and avoidance maneuvers in emergencies regardless of weather conditions, as it can obtain detailed information on space and obstacles not only in the front but also around them.

Autonomous Robot Adopting Multi-Axis Robotic Arm and ACO Algorithm

The autonomous robot being introduced aims to facilitate activities in hospitals, especially in the isolation wards, and bio/chemical laboratories. The text begins with introducing the parallelogram design of the robot, which permits 3 degrees of freedom (DoF), comprising 2 translational axes and 1 rotational axis. Macanum wheels provide high maneuverability and dexterity regarding robot motion, and its dynamic kinematic analysis is encompassed in the passage. Then, the essay specifically explains the methodology for testing the robot’s path-planning competence. Adopted by the robot, ant colony optimization (ACO) is a route-planning algorithm that has strong potential. It can deal with convoluted map configurations and has the value of incorporating advanced route planning and mapping technologies including SLAM. The essay then displays and analyzes the results from the test runs by inserting ACO into the route planning of a hospital map. Finally, the essay elicits the challenges and discusses the opportunities that the technologies being applied and how can the entire robot design be elaborated for a higher investigation value.

ZLN005 alleviates PBDE-47 induced impairment of mitochondrial translation and neurotoxicity through PGC-1α/ERRα axis

Recent studies are identified the mitochondria as critical targets of 2, 2′, 4, 4′-tetrabromodiphenyl ether (PBDE-47) induced neurotoxicity. This study aimed at examining the impact of PBDE-47 exposure on mitochondrial translation, and its subsequent effect on PBDE-47 neurotoxicity. The Sprague-Dawley (SD) rat model and neuroendocrine pheochromocytoma (PC12) cells were adopted for the measurements of mitochondrial ATP levels, mitochondrial translation products, and expressions of important mitochondrial regulators, such as required meiotic nuclear division 1 (RMND1), estrogen-related receptor α (ERRα), and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α). To delve into the role of PGC-1α/ERRα axis in mitochondrial translation, 2-(4-tert-butylphenyl) benzimidazole (ZLN005) was employed. Both cellular and animal model results shown that PBDE-47 impeded PGC-1α/ERRα axis and mitochondrial translation. PBDE-47 suppressed mitochondrial function in rat hippocampus and PC12 cells by decreasing relative mitochondrial DNA (mtDNA) content, mitochondrial translation products, and mitochondrial ATP levels. Particularly, ZLN005 reversed PBDE-47 neurotoxicity by enhancing mitochondrial translation through activation of PGC-1α/ERRα axis, yet suppressing PGC-1α with siRNA attenuates its neuroprotective effect in vitro. In conclusion, this work highlights the importance of mitochondrial translation in PBDE-47 neurotoxicity by presenting results from cellular and animal models and suggests a potential therapeutic approach through activation of PGC-1α/ERRα axis. Environmental implicationPBDEs have attracted extensive attention because of their high lipophilicity, persistence, and detection levels in various environmental media. Increasing evidence has shown that neurodevelopmental disorders in children are associated with PBDE exposure. Several studies have also found that perinatal PBDE exposure can cause long-lasting neurobehavioral abnormalities in experimental animals. Our recent studies have also demonstrated the impact of PBDE-47 exposure on mitochondrial biogenesis and dynamics, leading to memory and neurobehavioral deficits. Therefore, we explore whether the pathological mechanism of PBDE-47-induced neurotoxicity involves the regulation of mitochondrial translation through the PGC-1α/ERRα axis.

Effectiveness and Safety of Preoperative Halo Gravity Traction-Assisted Posterior Spinal Fusion Surgery for Severe and Rigid Scoliosis: A Comparative Matched-Cohort Study

Background. Severe and rigid scoliosis poses significant challenges in surgical correction, and innovative approaches are continually sought to enhance effectiveness and ensure patient safety. Halo-gravity traction (HGT) continues to be a vital tool in managing severe spinal conditions, offering a nonsurgical or preoperative approach to address spinal deformities. However, the correction effect that HGT can achieve for severe and rigid spinal deformity is currently unclear and the impact of HGT on the selection of spinal osteotomy grade was still unknown. Methods. A retrospective matched-cohort study was conducted and a total of 74 patients from January 2018 to December 2021 in our institution were finally enrolled in this study, including 27 patients in the HGT group and 47 patients in the non-HGT group based on whether patients receive HGT or not. Comprehensive assessments including radiographic outcomes, surgical parameters, and clinical complications were collect and analyzed before and after correction surgery. Results. Of the patients included in the HGT group, 21 had thoracic curvature and 6 had thoracolumbar/lumbar curvature, compared with 38 and 9 in the non-HGT group, respectively (P=0.66). There was no significant difference in the etiologies of scoliosis between two groups (15/7/3/2 vs. 25/16/4/2, P=0.85). The main curve in HGT and non-HGT groups were corrected from an average of 113.69°–51.25° and 111.94°–63.79° (P<0.01). For the HGT group, the mean correction rate of focal kyphosis (FK) was 45.43%, which was significantly higher than those in the non-HGT group (33.98%, P<0.05). There were no statistically significant differences in preoperative parameters of sagittal vertical axis (SVA) (P=0.13) or thoracic kyphosis (TK) (P=0.07) between the two groups. Postoperatively, the HGT group showed significantly lower values in SVA (P=0.001) and TK (P=0.001) compared to the non-HGT group. However, there was no significant difference in the imaging parameters coronal vertical axis (CVA) and apical vertebral translation (AVT) between the two groups (P>0.05). In the preoperative surgical planning phase before HGT treatment, 26 patients were initially considered candidates for 3-column osteotomy (3CO), while one patient was evaluated as suitable for posterior column osteotomy (PCO). Following HGT treatment, the assessment changed with 11 patients identified as candidates for 3CO and 16 patients deemed suitable for PCO. The application proportion of 3CO was significantly higher in the non-HGT group than in the HGT group (P<0.05). The mean blood loss of the non-HGT group was significantly greater than that of the HGT group (666.67 ± 486.55 ml vs. 1024.47 ± 718.46 ml, P<0.05), but the surgical time showed no difference between the two groups (297.33 ± 66.89 mins vs. 299.15 ± 56.73 mins, P=0.90). The incidence of complications in the HGT group was 7.4%, which was significantly lower than that of the non-HGT group (P<0.05). Conclusion. This study showed that the use of HGT, as a feasible and safe strategy, has superior efficacy and safety for treating severe and rigid scoliosis and can reduce the level of osteotomy used during surgery to some extent.

Effect of vestibular loss on head-on-trunk stability in individuals with vestibular schwannoma

The vestibulo-collic reflex generates neck motor commands to produce head-on-trunk movements that are essential for stabilizing the head relative to space. Here we examined the effects of vestibular loss on head-on-trunk kinematics during voluntary behavior. Head and trunk movements were measured in individuals with vestibular schwannoma before and then 6 weeks after unilateral vestibular deafferentation via surgical resection of the tumor. Movements were recorded in 6 dimensions (i.e., 3 axes of rotation and 3 axes of translation) using small light-weight inertial measurement units while participants performed balance and gait tasks. Kinematic measures differed between individuals with vestibular schwannoma (at both time points) and healthy controls for the more challenging exercises, namely those performed in tandem position or on an unstable surface without visual input. Quantitative assessment of the vestibulo-ocular reflex (VOR) revealed a reduction in VOR gain for individuals with vestibular schwannoma compared to control subjects, that was further reduced following surgery. These findings indicated that the impairment caused by either the tumor or subsequent surgical tumor resection altered head-on-trunk kinematics in a manner that is not normalized by central compensation. In contrast, we further found that head-on-trunk kinematics in individuals with vestibular schwannoma were actually comparable before and after surgery. Thus, taken together, our results indicate that vestibular loss impacts head-on-trunk kinematics during voluntary balance and gait behaviors, and suggest that the neural mechanisms mediating adaptation alter the motion strategies even before surgery in a manner that may be maladaptive for long-term compensation.

Structure of Argon Solid Phases Formed from the Liquid State at Different Isobaric Cooling Rates

By the method of molecular dynamics, computer simulation of the processes of isobaric cooling of argon particle systems under initial conditions with a temperature of 150 K at pressure values from 0.1 to 4 MPa to a temperature of 40 K with cooling rates of 108, 109, 1010, 1011 and 1012 K/s was performed. As a result of a computer experiment, coordinate arrays of particles were obtained, which were subjected to the procedure of three-dimensional Voronoi partitioning to identify and calculate the number of elementary cells of the crystal structure. Analysis of the structure of argon solid phases formed during isobaric cooling allowed us to deduce an estimated pattern between the concentration of FCC (face-centered cubic) cells in solid argon and the cooling rate from the liquid state. The evaluation of the orientation of the axes of translation of crystal cells in the array of particle coordinates made it possible to classify the solid phases formed as a result of cooling as single crystals, glassy media with the inclusion of clusters and single cells of FCC structures. It was revealed that during isobaric cooling at a rate not exceeding 108 K/s, argon completely crystallizes, at isobaric cooling rates of 109–1010 K/s, the union of elementary cells of the crystal structure into clusters is observed in glassy argon, and at rates of 1011 K/s and higher at pressures of 1 MPa and lower, solid vitreous phases of argon are formed in which no crystal structure cells are detected.

Influences of ink-bottle effect evolution on water retention hysteresis of unsaturated soils: An experimental investigation

The ink-bottle effect, resulting from the non-uniformity of pore structure, plays a significant role in the hydraulic behaviour of soils. In this paper, a series of laboratory tests including standard mercury intrusion porosimetry (MIP), intrusion-extrusion cyclic MIP (IEC-MIP), and scanning electron microscopy (SEM) were conducted on two soils (a Nanyang expansive clay and a Kaolin mixture) to examine the evolution pattern of ink-bottle effect in soils with different initial void ratios. To evaluate the impact of such evolution on the soil-water retention behaviour, the axis translation and vapour equilibrium techniques were utilised to measure the water retention curve of the tested soils (SWRC). A key part of the analysis involved a separation between pore bodies (or ink-bottle pores) and pore throats to facilitate a more thorough examination of the pore structure. The test results indicated that the reduction in soil volume during compression is mainly attributed to the reduction in pore body size, whereas the pore throat size remains relatively constant. Therefore, the ink-bottle effect would weaken with a decreasing initial void ratio, which will reduce the hysteresis potential of soils, manifesting as a contraction of the SWRC hysteresis loop. Additionally, under a fixed void ratio but with decreasing pore size, the ink-bottle effect will also weaken, which will reduce the distance between the drying and wetting curves with increasing matric suction. Finally, the mechanisms regarding how the evolution of ink-bottle effect during soil deformation influences water retention hysteresis were addressed.

Laser Glass deposition of single-mode glass fibers for the fabrication of chip-scale photonic circuits

The use of glass, particularly fused silica (FS), instead of polymers or semiconductors as optical waveguide material is advantageous due to broadband transmission, reduced propagation losses, and enhanced thermal and mechanical stability. In this contribution, laser glass deposition for the chip-scale fabrication of FS-based optical waveguides is investigated. We use a CO2 laser with emission at a wavelength of 10.6 µm to weld conventional single-mode glass fibers onto a FS substrate, with the aim of maintaining the waveguide properties of the fibers. Synchronized translational and rotational axis movements allow for positioning of the waveguides in arbitrary geometries. Furthermore, a CO2 laser-based cleaving method is introduced, which facilitates on-chip creation of waveguide end facets for optical coupling. An analysis of the cleave geometry in dependence on process parameters as well as optical coupling losses are presented. Coupling losses of 0.88 dB for a laser-cleave and propagation losses of 0.56 dB/cm for a 10 cm on-chip welded fiber were achieved. The results pave the way for on-chip integration of fiber-based systems like lasers, sensing devices or optical communication networks.

Dynamics of an omnidirectional pendulum energy harvester: A comparative analysis between numerical and experimental results

The spherical pendulum is a mathematically interesting model that has been studied extensively in the past. In the field of energy harvesting however, the pendulum energy harvesters are generally confined to planar motions. This minimisation of the available degrees of freedom potentially limits the areas of application of the energy harvester, and certainly its overall capability. In this work an omnidirectional pendulum energy harvester is proposed in the form of a two degree of freedom system which has the potential to harvest energy from motions along the three axes of translation and from the three corresponding rotations about those axes. The dynamics of such an energy harvester are examined experimentally for different power take-off modes and are subsequently compared to numerical predictions from an analytical model. An optimal operational point is proposed for the harvester and it is shown how an up-sweep and down-sweep of the excitation frequency can significantly broaden the operational range of the energy harvester by up to 130%.

RADT-47. MARGIN REDUCTION WITH THE INTRODUCTION OF INTRA-FRACTIONAL MONITORING USING IDENTIFY SGRT FOR FRAMELESS STEREOTACTIC CRANIAL RADIOSURGERY (SRS)

Abstract The purpose of this study was to evaluate the potential for margin reduction in clinical treatment settings based on the accuracy of Varian Identify SGRT (Surface-Guided Radiation Therapy). The study considered various factors such as patient setup variations, intrafraction movement, and unique facial features. Identify version 2.3.1 was installed on a Truebeam v2.7 system and commissioned according to AAPM TG3021 test recommendations. Identify generated reports on patient offsets in all six degrees of freedom during motion monitoring. These offsets were retrospectively compared with radiographic images (CBCT and MV planar images) to determine the accuracy of patient positioning achieved using surface guidance. A retrospective analysis of 36 patients was performed for a total of 125 fractions. The characteristics of the patient cohort (age range from 39 – 92 years) consisted of a mixture of 8 benign, 28 malignant lesions, 11 single, 25 standard fully-fractionated treatments and anatomical sites such as parietal, frontal, ventricle, base of skull, pons and acoustic neuromas. RESULTS: show that for this clinical cohort, the variance between Identify and radiographic imaging ranges from -0.02 to 0.08 cm, -0.09 to 0.10 cm, -0.09 to 0.09 cm and -0.81 to 0.74 degrees for the vertical, longitudinal, lateral and rotation respectively. This average variance in the translational axes is 0.0cm ± 0.0014 cm, indicating no directional preference. The 3D vector of the displacement detected achievable by Identify is 1 mm within a 95% confidence interval (CI). Based on the findings, the researchers concluded that a minimum GTV-PTV (Gross Tumor Volume-Planning Target Volume) margin of 1 mm is appropriate for intrafraction monitoring with Identify SGRT on the TrueBeam system for stereotactic cranial treatments. This information can increase the radiation oncologist's confidence in patient positioning during treatment delivery and potentially lead to a decrease in the GTV-PTV margin.