Movie Recording Research Articles

Workflow Analysis of Laparoscopic Nissen Fundoplication in Infant Pigs—A Model for Surgical Feedback and Training

Many fields use workflow analysis to assess and improve performance of complex tasks. In pediatric endosurgery, workflow analysis may help optimize operative planning and motor skills by breaking down the procedure into particular phases, evaluating these steps individually, and supplying feedback to the surgeon. To develop a module of computer-based surgical workflow analysis for laparoscopic Nissen fundoplication(LNF) and to evaluate its applicability in an infant pig model. LNF was performed in 12 pigs (weight, 7-10 kg) by a single surgeon. Based on synchronized intra and extracorporal movie recordings, the surgical workflow was segmented into temporal operative phases(preparation, dissection, reconstruction and conclusion). During each stage, all actions were recorded in a virtual timeline using a customized workflow editor. Specific tasks, such as knot-tying, were evaluated in detail.Time necessary to perform these actions was compared throughout the study. While time required for the preparation decreased by more than 70% from 4577 to 1379 seconds,and the dissection phase decreased from 2359 to 399 seconds (pig 1 and 12, respectively), the other two phases remained relatively stable. Mean time to perform the entire suture and a 5-throw knot remained constant as well. Our workflow analysis model allows the quantitative evaluation of dynamic actions related to LNF.This data can be used to define average benchmark criteria for the procedures that comprise this operation. It thereby permits task-oriented refinement of surgical technique as well as monitoring the efficacy of training.Although preoperative preparation time decreased substantially, and dissection became faster, time required for the reconstruction and conclusion phases remained relatively constant for a surgeon with moderate experience.Likewise, knot-tying did not accelerate in this setting.S-117

Correlação entre diferentes métodos de avaliação funcional da marcha de ratos com lesão por esmagamento do nervo isquiático

Foi realizado um estudo da correlação entre diferentes métodos de avaliação funcional do nervo ciático de ratos após lesão por esmagamento. Foram empregados no estudo 25 ratos da linhagem Wistar, de peso médio em torno de 250 g, submetidos a esmagamento controlado do nervo e avaliados por dois métodos convencionais para obtenção do índice funcional do ciático (IFC), baseados respectivamente na medida manual e computadorizada de parâmetros das impressões das pegadas dos animais, e por um novo método desenvolvido pelos autores, baseado na filmagem das pegadas e medida dos mesmos parâmetros, no 1º, 7º, 14º e 21º dias de pós-operatório, sendo feita a comparação com os valores obtidos no pré-operatório e entre os diferentes métodos nos vários períodos. Os resultados mostraram que o método da medida dos parâmetros pela filmagem das pegadas permite melhor visualização da pata acometida pela lesão do nervo e que este método se correlaciona com positivamente com os convencionais, já a partir da primeira semana de pós-operatório, desde que seja empregada a mesma fórmula para o cálculo do IFC.

A new legal strategy for copyright owners on the internet: MGM v. Grokster

The paper is an in-depth analysis and discussion of the legal actions and court cases concerning peer-to-peer file sharing software on the internet. The US District Court, US Circuit Court of Appeals and US Supreme Court cases analysed involve actions by major movie studios, record companies and song publishers against two major suppliers of the software, Grokster and StreamCast. Fifty million copies of these companies' free software is in use by internet subscribers who use the software to illegally download copyrighted materials. The US Supreme Court decision discussed ultimately holds Grokster and StreamCast liable for inducing these illegal downloads. The decision will have far reaching effects on future software development and marketing of movies and music on the internet.

The Neurofibromatosis Type 1 Gene Product Neurofibromin Enhances Cell Motility by Regulating Actin Filament Dynamics via the Rho-ROCK-LIMK2-Cofilin Pathway

Neurofibromin is a neurofibromatosis type 1 (NF1) tumor suppressor gene product with a domain that acts as a GTPase-activating protein and functions, in part, as a negative regulator of Ras. Loss of neurofibromin expression in NF1 patients is associated with elevated Ras activity and increased cell proliferation, predisposing to a variety of tumors of the peripheral and central nervous systems. We show here, using the small interfering RNA (siRNA) technique, that neurofibromin dynamically regulates actin cytoskeletal reorganization, followed by enhanced cell motility and gross cell aggregation in Matrigel matrix. NF1 siRNA induces characteristic morphological changes, such as excessive actin stress fiber formation, with elevated negative phosphorylation levels of cofilin, which regulates actin cytoskeletal reorganization by depolymerizing and severing actin filaments. We found that the elevated phosphorylation of cofilin in neurofibromin-depleted cells is promoted by activation of a Rho-ROCK-LIMK2 pathway, which requires Ras activation but is not transduced through three major Ras-mediated downstream pathways via Raf, phosphatidylinositol 3-kinase, and RalGEF. In addition, the exogenous expression of the NF1-GTPase-activating protein-related domain suppressed the NF1 siRNA-induced phenotypes. Neurofibromin was demonstrated to play a significant role in the machinery regulating cell proliferation and in actin cytoskeletal reorganization, which affects cell motility and adhesion. These findings may explain, in part, the mechanism of multiple neurofibroma formation in NF1 patients.

The history of consumer magnetic video tape recording, from a rarity to a mass product

Since the first experiments on magnetic recording by Valdemar Poulsen in 1898 the use of this technology has grown tremendously and magnetic storage is used in almost every home in the world. A special challenge was the recording of video signals which need a high bandwidth. In the 1950s, television broadcasts had started which created a need for storage in the broadcast world. The first broadcast recorder was the Quadruplex from Ampex in 1956. Later solutions were found for application in the consumer market. Better mechanics, magnetic tapes and recording heads allowed the mass production of a cheap consumer recorder. The size and weight decreased tremendously and portable camcorders are very common. Recording of broadcasts, video rental and home movies are now very popular. The factors which contributed to the maturing of this technology will be reviewed in this paper.

The postural reaction to the drop of a hindlimb support in the standing cat remains following sensorimotor cortical ablation

The postural response to an unexpected drop of either hindlimb platform was studied in the freely standing cat. The vertical forces, the forelimb electromyographic (EMG) activities and the movement of the trunk were analysed. A stereotyped diagonal pattern of support was observed. The imposed unloading of one hindlimb was followed by unloading of the diagonally opposite forelimb and loading of the two other limbs. In the ipsilateral loaded forelimb, the force increase is preceded by an activation of the biceps and is concomitant with a triceps coactivation. In the contralateral unloaded forelimb, reciprocal changes of biceps (activation) and triceps (inhibition) were observed and preceded the force decrease. Lateral or vertical displacement or rotation of the vertebral column at the high thoracic level, as evidenced by movie recording, began no earlier than 100 ms after the hindlimb drop and thus followed the EMG changes. Unilateral sensorimotor cortex ablation had no effect on this pattern or on the latencies of forelimb myographic responses. These results suggest that the hindlimb drop triggers stereotyped forelimb EMG responses which are organized centrally and that these responses are not mediated via a sensorimotor cortical loop.

The functional morphology of the musculature of squid (Loliginidae) arms and tentacles.

The arms and tentacles of squid (Family Loliginidae: Sepioteuthis sepioidea (Blainville), Loligo pealei (LeSueur), Loligo plei (Blainville), Loliguncula brevis (Blainville)) do not possess the hardened skeletal elements or fluid-filled cavities that typically provide skeletal support in other animals. Instead, these appendages are made up almost entirely of muscle. It is suggested here that the musculature serves as both the effector of movement and as the skeletal support system itself. High-speed movie recordings were used to observe prey capture by loliginid squid. Extension of the tentacles (1 pair) during prey capture is probably brought about by contraction of transverse muscle fibers and circular muscle fibers. Contraction of longitudinal muscle fibers causes retraction of the tentacles. Torsion of the tentacles during extension may be the result of contraction of muscle fibers arranged in a helical array. The inextensible but manipulative arms (4 pairs) may utilize a transverse muscle mass to resist the longitudinal compression caused by contraction of the longitudinal muscles which bend the arms. A composite connective tissue/muscle helical fiber array may twist the arms.

Current‐induced sediment movement in the deep Florida Straits: Critical parameters

A time‐lapse movie of the seabed at 710 m in the Florida Straits shows an irregular sequence of sediment ripple migration and suspension events, occupying 17% of the 43‐day duration of the record. Sediment in the region is a moderately sorted carbonate medium sand. Simultaneous current meter records at various positions in and above the benthic boundary layer are compared in various ways with the movie record to develop reliable predictive criteria for sediment motions in situ. With initiation and termination of sediment ripple migration predicted to occur when mean current at 3‐m elevation is 24 and 22 cm/s, respectively, 96% of the record is correctly predicted.