Serpentine Movement Research Articles

Comparison of Electrothermal Ablation and Electrolyte Plasmalization Devices Based on the Mechanical Properties of Anterior Cruciate Ligament Femoral Attachment Following Partial Debridement: A Biomechanical Study Using a Porcine Model.

Purpose This study aimed to clarify whether differences in ablation devices used in the knee joint during partial debridement of the proximal end of the femoral attachment of the anterior cruciate ligament (ACL) affect the mechanical properties of the femur-ACL-tibia complex. Methods Electrothermal ablation was generated from Vulcan for the left knees, and radiofrequency ablation was generated from Werewolf Flow 50 Wand for the right knees. The probes were set to the default setting of 120 W and 150 W for Vulcan and Werewolf Flow 50 Wand, respectively. To mimic partial debridement in remnant tissue-preserving (RTP) ACL reconstruction, the bipolar ablation mode and serpentine movements were employed while in contact with the femoral fan-like extension fibers of the ACL. To simulate the arthroscopic environment, the model was immersed in a saline solution. The probes were applied for 60 s, and their biomechanical properties were evaluated. Results A significant difference was observed in the upper yield load between the two groups (Vulcan group, 107.1 ± 93.4 N; Werewolf group, 177.9 ± 108.8 N; P = 0.045). However, no significant differences were noted in linear stiffness (Vulcan group, 47.6 ± 30.9 N/mm; Werewolf group, 50.1 ± 30.5 N/mm; P = 0.85), maximum load (Vulcan group, 276.2 ± 171.8 N; Werewolf group, 397.7 ± 150.8 N; P = 0.26), or elongation at failure (Vulcan group, 6.1 ± 0.9 mm; Werewolf group, 11.6 ± 10.4 mm; P = 0.20) between the two groups. Conclusion The mechanical properties of the ACL after partial ACL femoral attachment debridement for RTP-ACL reconstruction were better when an electrolyte plasmalization device was used. When performing RTP-ACL reconstruction, surgeons must consider that the device used for partial femoral ACL stump debridement may affect the mechanical properties of the ACL remnant tissue. Clinical relevance When performing RTP-ACL reconstruction, surgeons must consider that the device used for partial femoral ACL stump debridement may affect the mechanical properties of the ACL remnant tissue.

Adaptive Transition Gait Planning of Snake Robot Based on Polynomial Interpolation Method

This paper mainly studies the transition gait planning by updating the parameters of snack robot motion control function through ROS nodes, including a straight running gait into a turning gait. In the practical scenario, when changing the control parameters, the joint angle of the snake robot will increase or decrease sharply, and the angular velocity and angular acceleration of the driving joints will also change, which results in oscillation and sideslip of the body. In the turning scene, the visual tracking will loss if the head joint of the snake robot causes the lateral movement and oscillation. To solve those problems, firstly, the dynamic model of the snake robot’s gait of serpentine movement is established. Then, we propose a method based on polynomial interpolation compensation to solve the body oscillation and sideslip caused by nodes updating. To further improve the efficiency of snake robot’s gait switching, an optimal dichotomy interpolation time search is proposed to realize the snake robot’s adaptive transition gait. Finally, some simulation experiments are verified the effectiveness of the proposed method.

A Snake-Like Robot with Envelope Wheels and Obstacle-Aided Gaits

Most of the current snake-like robots can only work in a specific environment, or only have a good movement effect in a certain gait. This paper presents a design for a snake-like robot to improve the adaptability of various environments. Each standard module of the snake-like robot has three degrees of freedom: yawing, rolling, and telescoping. The envelope passive wheels are used to enable the robot to move in complex environments such as a narrow passage. We verified some simple movements such as serpentine movement and rectilinear movement and designed a method for recovering from rollover when the robot is in straight state. In addition, two novel gaits, obstacle-aided concertina gait, and obstacle-aided gait through narrow corner, are proposed in this paper. We demonstrated the feasibility for passing the narrow corner by these gaits in experiments.

Detection of Visual Signatures of Marine Mammals and Fish within Marine Renewable Energy Farms using Multibeam Imaging Sonar

Techniques for marine monitoring have been greatly evolved over the past decades, making the acquisition of environmental data safer, more reliable and more efficient. On the other hand, the marine renewable energy sector has introduced dissimilar ways of exploring the oceans. Marine energy is mostly harvested in murky and high energetic places where conventional data acquisition techniques are impractical. This new frontier on marine operations brings the need for finding new techniques for environmental data acquisition, processing and analysis. Modern sonar systems, operating at high frequencies, can acquire detailed images of the underwater environment. Variables such as occurrence, size, class and behavior of a variety of aquatic species of fish, birds, and mammals that coexist within marine energy sites can be monitored using imaging sonar systems. Although sonar images can provide high levels of detail, in most of the cases they are still difficult to decipher. In order to facilitate the classification of targets using sonar images, this study introduces a framework of extracting visual features of marine animals that would serve as unique signatures. The acoustic visibility measure (AVM) is here introduced as technique of identification and classification of targets by comparing the observed size with a standard value. This information can be used to instruct algorithms and protocols in order to automate the identification and classification of underwater targets using imaging sonar systems. Using image processing algorithms embedded in Proviwer4 and FIJI software, this study found that acoustic images can be effectively used to classify cod, harbour and grey seals, and orcas through their size, shape and swimming behavior. The sonar images showed that cod occurred as bright, 0.9 m long, ellipsoidal targets shoaling in groups. Harbour seals occurred as bright torpedo-like fast moving targets, whereas grey seals occurred as bulky-ellipsoidal targets with serpentine movements. Orca or larger marine mammals occurred with relatively low visibility on the acoustic images compared to their body size, which measured between 4 m and 7 m. This framework provide a new window of performing qualitative and quantitative observations of underwater targets, and with further improvements, this method can be useful for environmental studies within marine renewable energy farms and for other purposes.

The Vibrio H-Ring Facilitates the Outer Membrane Penetration of the Polar Sheathed Flagellum.

The bacterial flagellum has evolved as one of the most remarkable nanomachines in nature. It provides swimming and swarming motilities that are often essential for the bacterial life cycle and pathogenesis. Many bacteria such as Salmonella and Vibrio species use flagella as an external propeller to move to favorable environments, whereas spirochetes utilize internal periplasmic flagella to drive a serpentine movement of the cell bodies through tissues. Here, we use cryo-electron tomography to visualize the polar sheathed flagellum of Vibrio alginolyticus with particular focus on a Vibrio-specific feature, the H-ring. We characterized the H-ring by identifying its two components FlgT and FlgO. We found that the majority of flagella are located within the periplasmic space in the absence of the H-ring, which are different from those of external flagella in wild-type cells. Our results not only indicate the H-ring has a novel function in facilitating the penetration of the outer membrane and the assembly of the external sheathed flagella but also are consistent with the notion that the flagella have evolved to adapt highly diverse needs by receiving or removing accessary genes.IMPORTANCE Flagellum is the major organelle for motility in many bacterial species. While most bacteria possess external flagella, such as the multiple peritrichous flagella found in Escherichia coli and Salmonella enterica or the single polar sheathed flagellum in Vibrio spp., spirochetes uniquely assemble periplasmic flagella, which are embedded between their inner and outer membranes. Here, we show for the first time that the external flagella in Vibrio alginolyticus can be changed as periplasmic flagella by deleting two flagellar genes. The discovery here may provide new insights into the molecular basis underlying assembly, diversity, and evolution of flagella.

Serpentine Movement of Filaria in Wet Mount Preparation: Aspirated from Breast Swelling

Serpentine Movement of Filaria in Wet Mount Preparation: Aspirated from Breast Swelling

Body size and seasonal body condition in two small coexisting desert snake species, the Saharan sand viper (Cerastes vipera) and the crowned leafnose (Lytorhynchus diadema)

The Saharan sand viper, Cerastes vipera, and the crowned leafnose, Lytorhynchus diadema, are small coexisting psammophilic desert snake species, consume primarily lizards and do not engage in male to male combat. They differ in that C. vipera is ovoviparous and L. diadema is oviparous, C. vipera moves by sidewinding while L. diadema uses serpentine movement and C. vipera is a sit-and-wait ambusher while L. diadema is an active hunter. Results showed that C. vipera was heavier than L. diadema per unit snout-vent length (SVL). We concluded that this was related to foraging, as L. diadema had to move quicker than L. diadema, and to reproduction, as C. vipera needed more abdominal space for developing embryos. Sexual size dimorphism was found in adults in both species and it appeared that ecological advantages took precedence over phylogenetic affinity in determining size differences. The relatively small size, ovoviparity, sandy habitat with sidewinding, and lack of male to male combat for C. vipera whereas oviparity and sandy habitat for L. diadema may explain partly sexual size dimorphism in these species. Females showed seasonal fluctuations in BCI in both species but males did not and C. vipera females showed greater fluctuations than L. diadema females. We concluded that the former resulted from higher energy costs of females than males and the latter because ovoviparity is costlier than oviparity.

The Motion Planning Research of Bionic Worming Crawling

On the basis of the PYR type joint kinematics, redundant manipulator motion planning and bionic motion about surrounded grasping, creeping crawling, serpentine movement is researched. The motion planning of the mechanical arm by grab and surrounded was carried out based on geometric analysis. The grasping operation model meets the operation conditions. According to the creeping, serpentine movement of the bionic motion principle, the 5 section of 11 degree of freedom, the bionic worming crawling and the snake like motion planning about 8 joints and 17 degrees of freedom mechanical arm were given, combined with a full range of joint mechanism design and kinematics theory.

Influence Evaluation of Fastener Stiffness Match on Subway Rail Switch Safety

To study the influence law of fastener stiffness match on subway rail switch safety, and select appropriate stiffness, the No.9 subway switch was taken as an example in this paper to carry out all the following work. Based on finite element method, the influence of fastener stiffness match on the vertical dynamic relative displacement of switch rail and dynamic gauge widening were analyzed. The result shows that: the design concept of 'soft upper and rigid lower' can effectively decrease the vertical relative displacement of switch rail, and avoid the load of switch rail in advance, and ensure the safety of structure strength; It also could slow down dynamic gauge widening and serpentine movement amplitude, and improve the safety and stability of train; To ensure the safety of train, the design conception of soft upper and rigid lower should be applied for the subway switch.

Serpentine Movements in a Patient With Chilaiditi's Sign

Serpentine Movements in a Patient With Chilaiditi's Sign

Sonographic Appearance of Ascaris and Typical Serpentine Movement

The aim of this study was to share the experience of serpentine movement of ascaris at different places in the abdomen. Ascaris worm is very common in Pakistan especially in children and infects the human bowels. In our experiences, we have seen ascaris in bowels, Stomach, CBD, intra-hepatic duct and gallbladder on ultrasonography. Some of these ascaris were alive, and they had typical serpentine movement. We recorded these cases on our video which will be shown during the presentation. The patient had various signs and symptoms ranging from acute intestinal obstruction, intermittent jaundice, right hypochondrium discomfort, mimicking to acute appendicitis. we saw ascaris in bowel, stomach, CBD, intreahepatic ducts, and gallbladder, and recorded their serpentine movement on video tape. This paper will highlight the sonographic features and will show on video the typical serpentine movement.

Toxin treasure in snake venoms: A protein biochemist's sandbox

Snakes have fascinated mankind since prehistoric times. They have been the symbol of love and hate, war and peace, good and evil, god and devil, and life and death; oftentimes they have been contradictory symbols within the same civilization. They are one of the few living organisms which evoke a response – positive or negative – when one hears a hissing from a snake or a rattling sound from a rattlesnake or even a mere mention of the word ‘snake’. Their mystical serpentine movement – a canonical feature of these unusual limbless organisms – makes one's skin crawl. Above all, the intense fascination probably arises from their deadly venoms, which when injected into the victim lead to death of even the healthiest individuals. Numbers of victims who succumb to snakebite range from 60000 to 100000 per year in the 21st Century1.

Obstacle-Resistant Deployment Algorithms for Wireless Sensor Networks

Node deployment is an important issue in wireless sensor networks (WSNs). Sensor nodes should be efficiently deployed in a predetermined region in a low-cost and high-coverage-quality manner. Random deployment is the simplest way to deploy sensor nodes but may cause unbalanced deployment and, therefore, increase hardware costs and create coverage holes. This paper presents the efficient obstacle-resistant robot deployment (ORRD) algorithm, which involves the design of a node placement policy, a serpentine movement policy, obstacle-handling rules, and boundary rules. By applying the proposed ORRD, the robot rapidly deploys a near-minimal number of sensor nodes to achieve full sensing coverage, even though there exist unpredicted obstacles with regular or irregular shapes. Performance results reveal that ORRD outperforms the existing robot deployment mechanism in terms of power conservation and obstacle resistance and, therefore, achieves better deployment performance.

1P1-A21 ウナギ型水中推進ロボットの形状変化が遊泳に及ぼす影響

The propulsion method based on the aquatic life has many advantages as compared with the screw propeller. We have been developed Eel-like swimming robots of prototype 1 and prototype 2. The efficiency of swimming behavior depends on the shape of the robot in the water. In this paper we report the effect of changing the head shape, entire length of Eel-like swimming robot, and the number of the progressive wave. The miniaturized head reduced fluid resistance and improved swimming speed of an Eel-like robot. Prototype 2 robot swims underwater completely and on the surface of the water. In the case of swimming by serpentine movement like snakes and eels, furthermore, the swimming efficiency is affected by the shape of the cross section of the body. So we changed it into circular and rectangular cross section, and investigated the effect to the swimming form and the swimming speed. The number of the progressive wave has as big influence on the swimming performances as robot shape.

Serpentine Locomotion Articulated Chain: ANA II

When humanity faces challenges in solving problems beyond their technical resources, and has no foundation to solve a problem, engineering must search for an answer developing new concepts and innovative frameworks to excel these limitations and travel beyond our capabilities. This project “Serpentine locomotion articulated chain: ANA II” is a self-contained robot built to evaluate the behavior of the platform being capable of serpentine movements, in a modular chain mechanical design, based on a master/slave architecture.

Sonographic appearance of ascaris and typical serpentine movement

Sonographic appearance of ascaris and typical serpentine movement

Ultrasonographic appearance of Ascaris lumbricoides in the small bowel.

Roundworm infestation, one of the most common helminthic diseases worldwide, is caused by Ascaris lumbricoides, one of the largest parasites that infests the human bowel. A lumbricoides is virtually universal at some stage of childhood in semitropical and tropical regions. This study describes our experience with the ultrasonographic appearance of intestinal ascariasis in 84 patients, 2.5 to 42 years of age, examined over 2 years beginning October 1997. The patients' conditions ranged from acute intestinal obstruction to no clinical features pertaining to obstruction. Ultrasonographic examination was performed with an Echocee power Doppler real-time unit with a variable-frequency 3.7-MHz convex, 7.5-MHz linear probe. In longitudinal section the Ascaris worm presented as a linear intraluminal mass with 3 or 4 linear echogenic interfaces; in the cross section, it was round, sometimes appearing as a "target" sign. Some worms also showed serpentine movements. Sonographic examination of the patients in the left lateral decubitus position after ingestion of water improved detection and visualization of the worms in some cases. It is concluded that A lumbricoides in the small bowel has a sonographic appearance that can be recognized by the wary observer.

Serpentine Locomotion Articulated Chain: ANA II

When humanity faces challenges in solving problems beyond their technical resources, and has no foundation to solve a problem, engineering must search for an answer developing new concepts and innovative frameworks to excel these limitations and travel beyond our capabilities. This project “Serpentine locomotion articulated chain: ANA II” is a self‐contained robot built to evaluate the behavior of the platform being capable of serpentine movements, in a modular chain mechanical design, based on a master/slave architecture.

Enhanced isolation of Serpulina hyodysenteriae by using sliced agar media.

A method has been developed for separating Serpulina hyodysenteriae, a large spirochete and the causative agent of swine dysentery (SD), from other fecal anaerobic bacteria in rectal and colonic swabs. This was done by cutting the blood agar in parallel cuts and streaking perpendicular to the cuts in the center of the petri dish. Migration of S. hyodysenteriae from the central streak was apparent by the presence of strong beta-hemolysis along the edges of the cuts. If only S. hyodysenteriae migrated in the cut, they migrated to the end of the cut. However, if both motile bacteria and S. hyodysenteriae migrated in the cut, the motile bacteria migrated to the end of the cut where they formed colonies and the S. hyodysenteriae located along the edges of the cut between the colonies of motile bacteria and the central streak. Although motile bacteria were present where S. hyodysenteriae located, the growth of the motile bacteria was partially inhibited since they rarely formed visible colonies and were low in number. The cut in the agar was thought to improve traction for the serpentine movement of the S. hyodysenteriae and for the flagellar movement of the motile bacteria. Use of sliced blood agar was superior to conventionally streaked blood agar in that (i) it was easier to see strong beta-hemolysis on sliced agar; (ii) frequently, a confirmatory diagnosis could be made using only one petri dish with sliced agar, thereby saving time and media; (iii) S. hyodysenteriae could sometimes be isolated free of other bacteria; and (iv) sliced agar was more effective in isolating S. hyodysenteriae from swine with chronic diarrhea and nondiarrhetic carriers of SD in which the shedding of S. hyodysenteriae was low.

Initiation of sperm motility after mating in the rat and hamster.

Unlike those of many mammals, rat and hamster spermatozoa do not appear to be fully activated at ejaculation. Most rat spermatozoa transported en masse to the uterus approximately 2 minutes after coitus were vigorously motile on recovery soon thereafter in uterine fluid, whereas a majority, and sometimes all, were immotile in samples collected less than 2 minutes after coitus from the anterior vagina of normal females and up to 15 minutes after coitus from the anterior vagina in females with obstructed cervices. Many of these immotile rat vaginal spermatozoa began instant vigorous movement upon exposure to Tyrode's solution or uterine fluid. Hamster spermatozoa recovered from the vagina about 2 minutes after coitus were also immotile or displayed only slow, languid serpentine movements, but that motility profile remained very similar in spermatozoa taken 0.5 hours to 6 hours after coitus from the uterus, which is essentially fluid-free in the hamster. In the hamster, actively motile spermatozoa were evident only in the isthmus of the (transilluminated) oviduct. As in the rat, immotile vaginal and uterine hamster spermatozoa instantly began vigorous progressive motility in vitro on contact with Tyrode's solution or rat uterine fluid. Immotile spermatozoa from the rat and hamster cauda epididymidis immediately became highly motile in Tyrode's solution, and they developed a somewhat less rapid flagellar beat in 150 mmol/L NaCl or KCl, with or without 2 mmol/L CaCl2. In contrast, dilution with an isotonic sucrose solution containing no ions, or only 2 mmol/L CaCl2, evoked very slow and transient movement of rat and hamster epididymal sperm tails.(ABSTRACT TRUNCATED AT 250 WORDS)