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There is no consensus on whether and when surgical treatment is indicated for combined hamartoma of the retina and retinal pigment epithelium (CHRRPE). We aim to discuss the benefits of surgical intervention and techniques that may improve the outcome. A 24-year-old man experienced progressive visual loss for 6 months in his left eye due to CHRRPE. At presentation, visual acuity was 1.3 LogMAR and fundoscopy revealed extensive tractional pre- and epiretinal membranes, subretinal exudation, and a vasoproliferative tumor in the inferior periphery. A complete vitrectomy was performed, while paying special attention to vitreous shaving at the vitreous base and removal of vitreoschisis-induced vitreous cortex remnants (VCR) from the retinal surface posterior to the vitreous base. Tractional membranes and internal limiting membrane were peeled, and the vasoproliferative tumor was excised. Silicone oil tamponade was removed 11 weeks after surgery. No intra- or postoperative complications occurred. Visual acuity improved to 0.8 LogMAR and remained stable for 48-month follow-up. Vitreoretinal surgery can prevent complications that occur with CHRRPE. In addition, visual function may improve even if the initial visual acuity is low. Timely and complete vitrectomy with extensive membranectomy and detection and removal of VCR is recommended to avoid complications in challenging CHRRPE.

Purpose The pathogenesis of proliferative vitreoretinopathy (PVR), the most important cause of retinal detachment surgery failure, is still not fully understood. We previously hypothesized a causal link between vitreoschisis-induced vitreous cortex remnants (VCR) and PVR formation. The purpose of this case report is to demonstrate this association by showing the clinical occurrence of PVR in the presence of VCR across the retinal surface, illustrated by histopathological analysis. Observations A 69-year-old male was referred because of widespread epiretinal membrane formation after treatment of recurrent retinal detachments. During surgery with extensive membrane peeling, a large continuous membrane was peeled from the superior arcade towards the inferior temporal mid-periphery. Histopathological analysis of this membrane revealed areas with different characteristics: paucicellular laminar collagen-rich areas, suggestive for VCR, areas with increased cellularity, and more fibrotic areas with low cellularity. The immunohistochemical analysis identified cell type variety in these areas: collagen-rich areas showed glial cells and hyalocytes, while in areas with high cellularity fibroblasts, macrophages and retinal pigment epithelial cells were found, which have previously been shown to play an important role in the development of PVR as they can transdifferentiate into myofibroblasts, which were seen in the more fibrotic areas. Conclusions and importance These findings support the theory that VCR have a role in PVR development, where VCR can act as a scaffold for fibrocellular proliferation. We suggest that the presence of VCR over the retinal surface should be qualified as a risk factor for PVR formation. Detection and adequate removal of VCR may improve the success rate of retinal detachment surgery.

Three-column osteotomy (3-CO) is a powerful technique in adult deformity surgery, and pedicle subtraction osteotomy (PSO) is the workhorse to correct severe kyphotic spinal deformities. Aging of the population, increasing cases of iatrogenic flat back deformities and understanding the importance of sagittal balance have led to a dramatic increase of this surgical technique. Surgery, however, is demanding and associated with high complication rates so that every step of the procedure requires meticulous technique. Particularly, osteotomy closure is associated with risks like secondary fracture, translation, or iatrogenic stenosis. This step is traditionally performed by compression or a cantilever maneuver with sometimes excessive forces on the screws or instrumentation. Implant loosening or abrupt subluxation resulting in construct failure and/or neurological deficits can result. The aim of this prospective registry study was to assess the efficacy and safety of our surgical PSO technique as well as the osteotomy closure by flexing a hinge-powered OR table. In a series of 84 consecutive lumbosacral 3-CO, a standardized surgical technique with special focus on closure of the osteotomy was prospectively evaluated. The surgical steps with the patients positioned prone on a soft frame are detailed. Osteotomy closure was achieved by remote controlled bending of a standard OR table without compressive or cantilever forces in all 84 cases. This technique carries a number of advantages, particularly the reversibility and the slow speed of closure with minimum force. There was not a single mechanical intraoperative complication such as vertebral body fracture, subluxation, or adjacent implant loosening during osteotomy closure, compared to external cohorts using the cantilever technique (p = 0.130). The feasibility of controlled 3-CO closure by flexing a standard OR table is demonstrated. This technique enables a safe, gentle closure of the osteotomy site with minimal risk of implant failure or accidental neurological injury.

En este artículo exploramos la condición de las OVA (las ediciones domésticas de anime) como formato bisagra entre la madurez narrativa del anime en los setenta y la narración compleja de los noventa en adelante. La metodología empleada parte del análisis narratológico inspirado por la poética histórica de los modos de narración realizada por David Bordwell. Así, atendiendo a las categorías de la cognoscibilidad, de la autoconsciencia y de la comunicabilidad, constatamos en los resultados y en las conclusiones que la presunta simplicidad narrativa atribuida al anime no es tal, y que las OVA analizadas —Twilight Q: Meikyū Bukken Fairu Go San Hachi (Mamoru Oshii, 1987), Gunbuster (H. Anno, 1988-89) y Otaku no Video (T. Mori, 1991)— se alzan como hitos clave para el asentamiento de otro tipo de narración en la industria de la animación japonesa contemporánea, uno que lejos de ser formulaico, tiene correspondencia con la estimulante experimentación narrativa internacional de las llamadas puzzle films. The status of OVAs (domestic editions of anime) is explored in this article as a hinge format between the narrative maturity of anime in the 1970s and the complex storytelling from the 1990s onwards. The methodology used is based on a narratological analysis inspired by the historical poetics of cinema carried out by David Bordwell. Thus, taking into account the categories of knowledgeability, self-consciousness and communicativeness, in the results and conclusions it was found that the presumed narrative simplicity attributed to anime is not such, and that the OVAs analyzed —Twilight Q: Meikyū Bukken Fairu Go San Hachi (Mamoru Oshii, 1987), Gunbuster (H. Anno, 1988-89) and Otaku no Video (T. Mori, 1991)— stand as key milestones in the establishment of another type of storytelling in the contemporary Japanese animation industry, one that, far from being formulaic, corresponds to the stimulating international narrative experimentation of the so-called puzzle films.

The objective of the present work is to investigate the induced stress and deformation of a crank shaft. For this purpose, Variable Compression Ratio (VCR) engine is tested at 16.5 compression ratio. Peak pressures were recorded at various crank angles. A Matlab code is generated for dynamic analysis. For structural analysis and factor of safety, a three dimensional model crank shaft was developed using solid works. Finite element analysis of AISI E4340 Forged steel and Aluminum alloy 7076-T6 materials are carried by using analysis software ANSYS. The obtained results are equivalent Von-Mises stress, total deformation and factor of safety at different crank angles for the two materials are analyzed. It is concluded that Aluminum alloy exhibits better results than forged steel.

Study Design: Broad narrative review. Objective: To review the evolution, operative technique, outcomes, and complications associated with posterior vertebral column resection. Methods: A literature review of posterior vertebral column resection was performed. The authors’ surgical technique is outlined in detail. The authors’ experience and the literature regarding vertebral column resection are discussed at length. Results: Treatment of severe, rigid coronal and/or sagittal malalignment with posterior vertebral column resection results in approximately 50–70% correction depending on the type of deformity. Surgical site infection rates range from 2.9% to 9.7%. Transient and permanent neurologic injury rates range from 0% to 13.8% and 0% to 6.3%, respectively. Although there are significant variations in EBL throughout the literature, it can be minimized by utilizing tranexamic acid intraoperatively. Conclusion: The ability to correct a rigid deformity in the spine relies on osteotomies. Each osteotomy is associated with a particular magnitude of correction at a single level. Posterior vertebral column resection is the most powerful posterior osteotomy method providing a successful correction of fixed complex deformities. Despite meticulous surgical technique and precision, this robust osteotomy technique can be associated with significant morbidity even in the most experienced hands.

Neuroscientific studies show that humans tend to stabilize their head orientation, while accomplishing a locomotor task. This is beneficial to image stabilization and in general to keep a reference frame for the body. In robotics, too, head stabilization during robot walking provides advantages in robot vision and gaze-guided locomotion. In order to obtain the head movement behaviors found in human walk, it is necessary and sufficient to be able to control the orientation (roll, pitch and yaw) of the head in space. Based on these principles, three controllers have been designed. We developed two classic robotic controllers, an inverse kinematics based controller, an inverse kinematics differential controller and a bio-inspired adaptive controller based on feedback error learning. The controllers use the inertial feedback from a IMU sensor and control neck joints in order to align the head orientation with the global orientation reference. We present the results for the head stabilization controllers, on two sets of experiments, validating the robustness of the proposed control methods. In particular, we focus our analysis on the effectiveness of the bio-inspired adaptive controller against the classic robotic controllers. The first set of experiments, tested on a simulated robot, focused on the controllers response to a set of disturbance frequencies and a step function. The other set of experiments were carried out on the SABIAN robot, where these controllers were implemented in conjunction with a model of the vestibulo-ocular reflex (VOR) and opto-kinetic reflex (OKR). Such a setup permits to compare the performances of the considered head stabilization controllers in conditions which mimic the human stabilization mechanisms composed of the joint effect of VOR, OKR and stabilization of the head. The results show that the bio-inspired adaptive controller is more beneficial for the stabilization of the head in tasks involving a sinusoidal torso disturbance, and it shows comparable performances to the inverse kinematics controller in case of the step response and the locomotion experiments conducted on the real robot.

Study Design: Literature review. Objective: The aim of this study was to provide an overview of the available intraoperative monitoring techniques and the evidence around their efficacy in vertebral column resection. Methods: The history of neuromonitoring and evolution of the modalities are reviewed and discussed. The authors’ specific surgical techniques and preferred methods are outlined in detail. In addition, the authors’ experience and the literature regarding vertebral column resection and surgical mitigation of neurologic alarms are discussed at length. Results: Risk factors for signal changes have been identified, including preoperative neurologic deficit, severe kyphosis, increased curve magnitude, and significant cord shortening. Even though no evidence-based treatment algorithm exist for signal changes, strategies are discussed that can help prevent alarms and address them appropriately. Conclusion: Through implementation of multimodal intraoperative monitoring techniques, potential neurologic injuries are localized and managed in real time. Intraoperative monitoring is a valuable tool for improving the safety and outcome of spinal deformity surgery.

Widely used in clinical practice surgical interventions directed to the correction of severe kyphotic spine deformities, i.e. Ponte osteotomy, Smith-Peterson osteotomy, pedicle subtraction osteotomy and vertebral column resection are presented. Surgical techniques, surgery planning based on spinal and pelvic sagittal contour parameters, treatment results are described.

Two main classes of reflexes relying on the vestibular system are involved in the stabilization of the human gaze: The vestibulocollic reflex (VCR), which stabilizes the head in space and the vestibulo-ocular reflex (VOR), which stabilizes the visual axis to minimize retinal image motion. The VOR works in conjunction with the opto-kinetic reflex (OKR), which is a visual feedback mechanism for moving the eye at the same speed as the observed scene. Together they keep the image stationary on the retina. In this work we present the first complete model of gaze stabilization based on the coordination of VCR and VOR and OKR. The model, inspired on neuroscientific cerebellar theories, is provided with learning and adaptation capabilities based on internal models. Tests on a simulated humanoid platform confirm the effectiveness of our approach.

Two main classes of reflexes relying on the vestibular system are involved in the stabilization of the human gaze: the vestibulocollic reflex (VCR), which stabilizes the head in space and the vestibulo-ocular reflex (VOR), which stabilizes the visual axis to minimize retinal image motion. Together they keep the image stationary on the retina.

In the peer-to-peer video-on-demand (P2P VoD) streaming applications, providing VCR-like operations is important but much challenging. In this paper, we propose a novel P2P scheme–Fibonacci ring overlay networks with distributed chunk storage, called FiRiNet, to reduce jump latency caused by VCR-like operations and avoid an adverse impact caused by VCR-like operations. In FiRiNet, video data is divided into chunks and stored at peers’ local storage in a distributed manner. A peer can achieve fast neighbor discovery to reduce jump latency by maintaining some neighbors in a set of concentric rings with Fibonacci sequence radii. Moreover, FiRiNet constructs the overlay networks and distributes the video data based on the stored chunks, which can make FiRiNet avoid an adverse impact caused by VCR-like operations and make FiRiNet resilient to the peer churn caused by VCR-like operations. Through simulations, we demonstrate that FiRiNet is an effcient and resilient scheme with low control overhead, short jump latency, and high streaming quality.

The sensitivity characteristics of two novel fully-analog uncalibrated read-out circuits, based on a suitable modification of the classic Wheatstone bridge topology, employed for resistive sensor measurements, are here described and discussed. The proposed circuits maintain the bridge characteristics of a simple architecture and an easy estimation technique. The proved advantages of these two solutions are related to the evaluation of about 5 resistive decades variations [1000 ÷10M0] and to the reduced error confined within ±2%. Moreover, it is here demonstrated that, in the proposed interfaces, sensitivity values are higher than those of the classic Wheatstone bridge, supply-voltage independent and can be set through a proper choice of the passive element values.

Gaze stabilization is essential for clear vision; it is the combined effect of two reflexes relying on vestibular inputs: the vestibulocollic reflex (VCR), which stabilizes the head in space and the vestibulo-ocular reflex (VOR), which stabilizes the visual axis to minimize retinal image motion. The VOR works in conjunction with the opto-kinetic reflex (OKR), which is a visual feedback mechanism that allows to move the eye at the same speed as the observed scene. Together they keep the image stationary on the retina. In this work we implement on a humanoid robot a model of gaze stabilization based on the coordination of VCR and VOR and OKR. The model, inspired by neuroscientific cerebellar theories, is provided with learning and adaptation capabilities based on internal models. We present the results for the gaze stabilization model on three sets of experiments conducted on the SABIAN robot and on the iCub simulator, validating the robustness of the proposed control method. The first set of experiments focused on the controller response to a set of disturbance frequencies along the vertical plane. The second shows the performances of the system under three-dimensional disturbances. The last set of experiments was carried out to test the capability of the proposed model to stabilize the gaze in locomotion tasks. The results confirm that the proposed model is beneficial in all cases reducing the retinal slip (velocity of the image on the retina) and keeping the orientation of the head stable.