Rocker Switch Research Articles

Impact of number of projections on image quality of X-ray Computed Tomography

Background and Aims: This research aims to find the image quality of the computed tomography (CT) imaging technique, in terms of noise as a function of the number of projections. Methods: The X-ray Computed Tomography set is started using the rocker switch and the MeasureCT32 program is allowed to run, all devices at two different projections (20 and 300) are implemented. Results: The results of the experiment made clear that increasing the number of projections effectively reconstructs high-quality images in CT image reconstructions, e.g. when implementing 300 projections. This was also clarified with a lower number of projections giving reduced quality of the image, as shown in 20 projections. Conclusions: As increasing, the number of projections that leads to obtain high-quality images, clearer, and less noisy in CT image reconstructions as shown in 300 projections. Thus, reducing the number of projections results in reducing image quality.

Statistical analysis of forest machines ergonomic parameters

The main technology currently used in wood harvesting in Russia is the cut-to-length technology (CTL) based on the use of two machine types: harvesters and forwarders. Powerful and manoeuvrable hydraulic manipulators (cranes) are a main part of the equipment of both the harvester and the forwarder. A statistical analysis of ergonomic parameters of the manipulator control system equipped with partial automation option is described in this article. Two machines were studied in natural field conditions. Differences in the frequency and duration of telescopic extension boom control activations were identified. The distributions of the extension boom use parameters for the crane of the logging machines were defined. It can be used to build various models for the analysis of promising crane design solutions. It is determined that the duration of the rocker switch single press has a log-normal distribution and the period between switch activations has an exponential distribution.

Ins and Outs of Rocker Switch Mechanism in Major Facilitator Superfamily of Transporters.

The major facilitator superfamily (MFS) of transporters consists of three classes of membrane transporters: symporters, uniporters, and antiporters. Despite such diverse functions, MFS transporters are believed to undergo similar conformational changes within their distinct transport cycles, known as the rocker-switch mechanism. While the similarities between conformational changes are noteworthy, the differences are also important since they could potentially explain the distinct functions of symporters, uniporters, and antiporters of the MFS superfamily. We reviewed a variety of experimental and computational structural data on a select number of antiporters, symporters, and uniporters from the MFS family to compare the similarities and differences of the conformational dynamics of three different classes of transporters.

Structural basis of the substrate recognition and inhibition mechanism of Plasmodium falciparum nucleoside transporter PfENT1

By lacking de novo purine biosynthesis enzymes, Plasmodium falciparum requires purine nucleoside uptake from host cells. The indispensable nucleoside transporter ENT1 of P. falciparum facilitates nucleoside uptake in the asexual blood stage. Specific inhibitors of PfENT1 prevent the proliferation of P. falciparum at submicromolar concentrations. However, the substrate recognition and inhibitory mechanism of PfENT1 are still elusive. Here, we report cryo-EM structures of PfENT1 in apo, inosine-bound, and inhibitor-bound states. Together with in vitro binding and uptake assays, we identify that inosine is the primary substrate of PfENT1 and that the inosine-binding site is located in the central cavity of PfENT1. The endofacial inhibitor GSK4 occupies the orthosteric site of PfENT1 and explores the allosteric site to block the conformational change of PfENT1. Furthermore, we propose a general “rocker switch” alternating access cycle for ENT transporters. Understanding the substrate recognition and inhibitory mechanisms of PfENT1 will greatly facilitate future efforts in the rational design of antimalarial drugs.

A Machine Learning-Based Approach for Quick Evaluation of Live Simulations in Embodiment Design

AbstractSupporting product developers in early design phases with Live-Simulation can enhance the quality of early product designs. Live-Simulation can also facilitate a democratization of simulation and puts away pressure from simulation experts. In this paper, a machine learning based quick evaluation tool is proposed to support product developers in interpreting Live-Simulation results. The proposed tool enables a quick evaluation of the Live-Simulation results and enables product developers to further enhance their simulations. The tool is shown within a use case in bike rocker switch design.

Semi-Autonomous Trolley Cart

Semi-Autonomous Trolley Cart is design to reduce the chances of flight attendants from getting injuries while performing their duties. This project will help flight attendants to move the trolley cart comfortably and smoothly. The weight of this trolley including its loads weighs at approximately 25KG. It can move by itself using a rocker switch as this trolley is equipped with line following sensor underneath it. This trolley is also equipped with some electrical component. There is a line following sensor underneath the trolley. This sensor will follow a straight line that will be place along the aisle using a black tape. This project primarily focused on the trolley being a semi-autonomous and it will be controlled by switch.

Design and structural analysis of inbuilt car jack system

A Screw Jack is used to lift a heavy load. This jack is modified and made in such a way that it can be fitted to the frame of the vehicle. Hence when the jack operates, the car can be lifted up. The jack operation is made possible with the buttons fitted to the dashboard of the vehicle. In case of puncture or any other service, there is no need for external jack. The system is user-friendly such as in case of the power window. The rocker switch is used to enable the reverse operation of the jack too. The jack is operated by an electric motor powered by the car battery. The Rocker switches are placed inside a lock protected box, in order to prevent any accidents. The rocker switch can be accessed only when it is needed.

Fabriction of Mechanical Segway With Handle

Segway is a two-wheeled motorized personal vehicle consisting of a platform for the fleet mounted above an axle an upright post surmounted by handle with two guiding wheels, controlled by the rocker switches. Segway is mainly used for the short distance travel where there is no use of fuel and no pollution. The main objective of this project is to produce an easy way to move and a comfortable space for the user and reduce pollution as this model is eco-friendly. The present project proposes a cost effective and innovative design compared to the existing segway available in the market. The proposed project also aims to reduce the e-waste by eliminating few electronic components.

Innovative productivity improvements in forest operations: a comparative study of the Assortment Grapple using a machine simulator

Because of generally small log piles, loading forwarders during thinning is time consuming. The Assortment Grapple, an innovative grapple with an extra pair of claws which facilitates the handling of two assortments during one loading crane cycle, has been designed to decrease forwarders’ loading time consumption. A standardized experiment was performed in a virtual thinning stand using a machine simulator with the objectives to form guidelines for working with the Assortment Grapple and to analyse its development potential. Four experienced operators participated in the study. According to the results, the Assortment Grapple’s accumulating function is beneficial only when there are no remaining trees between piles loaded during the same crane cycle. In such cases, none of participating operators lost time, and 3 of 4 operators saved time notably. The problem with the remaining trees is the extra time required to steer the crane tip around them. Therefore, a harvester should place those log piles that are later to be forwarded together in the same space with no remaining trees between the piles. Furthermore, we recommend that the Assortment Grapple’s usability will be improved by adding an own rocker switch on the forwarder’s controls to command the extra claws.

Electronic Depth Adjustment in an Automatic Chest Compression Device for Rodents – Design and Implementation of a LabVIEW‐based Control Unit

IntroductionDespite best efforts of cardiopulmonary resuscitation (CPR), many patients still die or suffer severe cardio‐cerebral damage following cardiac arrest (CA). The quality of manual chest compressions (CC) rarely adheres to current guidelines with regards to CC rate, depth and fraction of time spent during CPR. Automated mechanical CC devices offer a reliable improvement in both the clinical arena and in research models. We describe the mechanical and programming aspects of the development of a depth controller for a pneumatic CC device for CPR in rodent CA model.Methods & ResultsIn order to electronically control the amplitude/depth of the vertical CC piston (Weil Institute of Critical Care Medicine, Palm Springs, CA; Fig 1) that is pneumatically displaced between 0 and maximally 2 cm 200 times min−1 (duty cycle 1:1), a horizontally moving wedge was connected to a rack gearbox driven by a low‐voltage motor (Fischertechnik, Waldachtal, Germany) along a fixed rack. The unit was connected to a horizontally sliding potentiometer to monitor the exact position of the wedge and, therefore, the piston displacement which itself was monitored through a second, vertically sliding potentiometer. Both potentiometers were connected to an USB 6343 data acquisition system (DAQ, National Instruments, Austin, TX). The motor was connected to two analogue outputs of the DAQ (for movement and direction) via a commercially available low‐voltage amplifier. Stepwise movement of the wedge in either direction could be controlled by a momentary rocker switch connected to two analogue input channels of the DAQ (for deeper and shallower compressions) and its LabVIEW software which was programmed to allow precise control of the wedge’s position.ConclusionsWe report the design and construction of an inexpensive, LabVIEW‐based control unit to electronically adjust CC depth in a rodent model of CA and CPR. Neither the hardware, nor the software required to perform this highly specialized application were commercially available. This custom‐designed and ‐built device achieved its purpose of allowing electronic control and recording of the CC depth in this rodent model with high reliability and precision. Moreover, it constitutes the necessary basis of pre‐programmed or feedback‐assisted adjustments of variable CC depth in the future to improve neurologically favorable outcome after CA.Support or Funding InformationThis work was supported, in part, by institutional funds, and a Merit Review Award (I01 BX003482) from the U.S. Department of Veterans Affairs Biomedical Laboratory R&D Service.Pneumatic chest compression device for rodents with added control unit for electronic depth adjustment.Figure 1

Towards a 3-D Technique to Determine the Geometric Path of Electric Current Flow Through a Contact System

The effective conductivity of a contact system is an important characteristic used to link the microstructure of the contact system to its performance. A resistor network model has been developed from the cross-sectional slices of a given electrical contact system. This allows the total resistance across the model and hence the total conductance of the system to be calculated. This resistor network model development is based on the contact interface, of the contact system, which is presented as a 3-D contact map. The 3-D contact map consists of contact spots that have been extended across the two bodies of the contact system as asperities. In this modeling process, a technique is developed that pictures any cross-sectional slice of the contact system and shows in which voxels the electric current flows. An X-ray computed tomography method is used to collect the data for visualizing the contact system and preparing the 3-D contact map. A 250-V, 16-A rated ac single-pole rocker switch is used as the contact system for investigation.

A 3D contact analysis approach for the visualization of the electrical contact asperities.

The electrical contact is an important phenomenon that should be given into consideration to achieve better performance and long term reliability for the design of devices. Based upon this importance, the electrical contact interface has been visualized as a ‘‘3D Contact Map’’ and used in order to investigate the contact asperities. The contact asperities describe the structures above and below the contact spots (the contact spots define the 3D contact map) to the two conductors which make the contact system. The contact asperities require the discretization of the 3D microstructures of the contact system into voxels. A contact analysis approach has been developed and introduced in this paper which shows the way to the 3D visualization of the contact asperities of a given contact system. For the discretization of 3D microstructure of contact system into voxels, X-ray Computed Tomography (CT) method is used in order to collect the data of a 250 V, 16 A rated AC single pole rocker switch which is used as a contact system for investigation.

Impact of Work Related Stress on Motion Stereotypic Responses

Stereotypes can be referred as conditioned reflexes which have become subconscious and automatic. In the present study efforts have been made to figure out how work stress affects motion stereotype. The study was performed on a group of pole manufacturing workers (n=44) having the age group of 45-54 years. The work related stress was evaluated in terms of CSI (Cardiovascular Stress Index) of the subjects on the basis of their heart rates. The subjects were divided into three groups (light stress, moderate stress and high stress) according to the percentile values of CSI. Direction of motion stereotype was determined for different control-display units, viz., rotary control knob and horizontal display , rotary control knob and vertical display, rotary control knob and circular display, and rocker switch in horizontal and vertical alignment for ‘on’ and ‘off’ response. Index of reversibility of the direction of motion stereotype was determined. Experiments were also performed for right and left handed workers separately. The response initiation time of the workers was computed by a digital timer. Results showed that there was no significant difference in the direction of motion stereotype between left and right handed workers. Significant difference (p<0.05 or less) in the direction of motion stereotype of the workers was observed in most of the control display combinations among different stress levels. The index of reversibility was decreased with increased stress level. It may be concluded that work related stress had a notable effect on motion stereotypic responses of the factory workers.

Molecular Dynamics Simulations of the Human Glucose Transporter GLUT1.

Glucose transporters (GLUTs) provide a pathway for glucose transport across membranes. Human GLUTs are implicated in devastating diseases such as heart disease, hyper- and hypo-glycemia, type 2 diabetes and caner. The human GLUT1 has been recently crystalized in the inward-facing open conformation. However, there is no other structural information for other conformations. The X-ray structures of E. coli Xylose permease (XylE), a glucose transporter homolog, are available in multiple conformations with and without the substrates D-xylose and D-glucose. XylE has high sequence homology to human GLUT1 and key residues in the sugar-binding pocket are conserved. Here we construct a homology model for human GLUT1 based on the available XylE crystal structure in the partially occluded outward-facing conformation. A long unbiased all atom molecular dynamics simulation starting from the model can capture a new fully opened outward-facing conformation. Our investigation of molecular interactions at the interface between the transmembrane (TM) domains and the intracellular helices (ICH) domain in the outward- and inward-facing conformation supports that the ICH domain likely stabilizes the outward-facing conformation in GLUT1. Furthermore, inducing a conformational transition, our simulations manifest a global asymmetric rocker switch motion and detailed molecular interactions between the substrate and residues through the water-filled selective pore along a pathway from the extracellular to the intracellular side. The results presented here are consistent with previously published biochemical, mutagenesis and functional studies. Together, this study shed light on the structure and functional relationships of GLUT1 in multiple conformational states.

Constrained postures and spatial S-R compatibility as measured by the Simon effect.

Whereas working under constrained postures is known to influence the worker's perceived comfort and health, little is known in regard to its influence on performance. Employing an Auditory Simon task while varying posture, we investigated the relationship between constrained postures and cognitive processes in three experiments. In Experiment 1 and 2, participants operated a rocker switch or a control knob with one hand either in front or in the back of their body and while either sitting or kneeling. Perceived musculoskeletal exertion was gathered with a questionnaire. Results of the first two experiments showed differently perceived comfort and a minor effect of constrained posture on cognitive performance. However, results indicated that spatial coding in the back compares to either a virtual turn of the observer towards the control device (front-device coding) or along the observer's hand (effector coding). To clarify this issue the rocker switch was operated with one or two hands in Experiment 3, showing a comparable coding only in the one-hand condition and indicating evidence for the effector-coding hypothesis in the back.

Crystal structure of a nitrate/nitrite exchanger.

SummaryMineral nitrogen in nature is often found in the form of nitrate (NO3-). Numerous microorganisms evolved to assimilate nitrate and use it as a major source of mineral nitrogen uptake1. Nitrate, which is central in nitrogen metabolism, is first reduced to nitrite (NO2-) through a two-electron reduction reaction2,3. The accumulation of cellular nitrite can be harmful because nitrite can be reduced to the cytotoxic nitric oxide. Instead, nitrite is rapidly removed from the cell by channels and transporters, or reduced to ammonium or dinitrogen through the action of assimilatory enzymes3. Despite decades of effort no structure is currently available for any nitrate transport protein and the mechanism by which nitrate is transported remains largely obscure. Here we report the structure of a bacterial nitrate/nitrite transport protein, NarK, from Escherichia coli, with and without substrate. The structures reveal a positively charged substrate-translocation pathway lacking protonatable residues, suggesting that NarK functions as a nitrate/nitrite exchanger and that H+s are unlikely to be co-transported. Conserved arginine residues form the substrate-binding pocket, which is formed by association of helices from the two halves of NarK. Key residues that are important for substrate recognition and transport are identified and related to extensive mutagenesis and functional studies. We propose that NarK exchanges nitrate for nitrite by a rocker-switch mechanism facilitated by inter-domain H-bond networks.

PREPROGRAMMED HEARING ASSISTANCE DEVICE WITH PROGRAM SELECTION USING A MULTIPURPOSE CONTROL DEVICE

A user programmable hearing aid allows a user to select acoustical configuration programs that provide optimum performance for the user. The user may cycle through and evaluate various available programs by operating a single digital rocker switch on the hearing aid housing to switch from one program to the next. When a preferred program is active, the user can press and hold an up control or down control of the digital rocker switch for an extended time to select the currently active program. The user can then use the digital rocker switch to adjust the audio gain for the selected program. The hearing aid may also operate in a Configuration Mode wherein configuration settings may be changed by operating the up and down controls of the digital rocker switch. In the Configuration Mode, a clinician or patient may easily change configuration settings manually, with no need to connect the apparatus to a computer or other programming interface.

The Effect of Pressurized Space Gloves on Operability of Cursor Controls, Mobility, and Strength

Space Human Factors Engineering (SHFE) researchers at Johnson Space Center (JSC), in collaboration with the Extravehicular Activity (EVA) Suit Team, performed a glove box study investigating operability of cursor controls, mobility, and strength of the participants while wearing pressurized gloves. Performance time was collected under a range of glove pressures (0, 0.8, 4.3, 6.3, and 8.1 psid), as well as bare-handed. Controls tested included a Castle switch, Rocker switch, and Trackball. The study was undertaken to determine impacts of operating controls under higher than nominal (i.e., > 4.3 psid) suit pressures. Operability when using cursor control devices was tested with an interactive software task representative of the types of actions that will be required to interact with space vehicle displays (display navigation and selection of a target). Results indicate that cursor control devices can be operated at pressures up to 8.1 psid, albeit with some difficulty. With respect to mobility, increased pressure seemed to affect thumb mobility more than the fingers. As the number of participants was limited in this initial feasibility study, further studies should be performed with a larger number of participants to evaluate performance with different hand/glove sizes, as well as with alternative device designs that are more ergonomically flexible and forgiving of hand and finger dimension changes brought on by increases in pressure. Results from this study may have implications for other gloved task environments.

A model of novice and expert navigation performance in constrained-input interfaces

Many interactive systems require users to navigate through large sets of data and commands using constrained input devices—such as scroll rings, rocker switches, or specialized keypads—that provide less power and flexibility than traditional input devices like mice or touch screens. While performance with more traditional devices has been extensively studied in human-computer interaction, there has been relatively little investigation of human performance with constrained input. As a result, there is little understanding of what factors govern performance in these situations, and how interfaces should be designed to optimize interface actions such as navigation and selection. Since constrained input is now common in a wide variety of interactive systems (such as mobile phones, audio players, in-car navigation systems, and kiosk displays), it is important for designers to understand what factors affect performance. To aid in this understanding, we present the Constrained Input Navigation (CIN) model, a predictive model that allows accurate determination of human navigation and selection performance in constrained-input scenarios. CIN identifies three factors that underlie user efficiency: the performance of the interface type for single-level item selection (where interface type depends on the input and output devices, the interactive behavior, and the data organization), the hierarchical structure of the information space, and the user's experience with the items to be selected. We show through experiments that, after empirical calibration, the model's predictions fit empirical data well, and discuss why and how each of the factors affects performance. Models like CIN can provide valuable theoretical and practical benefits to designers of constrained-input systems, allowing them to explore and compare a much wider variety of alternate interface designs without the need for extensive user studies.

Ribosomal protein L3 functions as a ‘rocker switch’ to aid in coordinating of large subunit-associated functions in eukaryotes and Archaea

Although ribosomal RNAs (rRNAs) comprise the bulk of the ribosome and carry out its main functions, ribosomal proteins also appear to play important structural and functional roles. Many ribosomal proteins contain long, nonglobular domains that extend deep into the rRNA cores. In eukaryotes and Archaea, ribosomal protein L3 contains two such extended domains tethered to a common globular hub, thus providing an excellent model to address basic questions relating to ribosomal protein structure/function relationships. Previous work in our laboratory identified the central ‘W-finger’ extension of yeast L3 in helping to coordinate ribosomal functions. New studies on the ‘N-terminal’ extension in yeast suggest that it works with the W-finger to coordinate opening and closing of the corridor through which the 3′ end of aa-tRNA moves during the process of accommodation. Additionally, the effect of one of the L3 N-terminal extension mutants on the interaction between C75 of the aa-tRNA and G2921 (Escherichia coli G2553) of 25S rRNA provides the first evidence of the effect of a ribosomal protein on aa-tRNA positioning and peptidyltransfer, possibly through the induced fit model. A model is presented describing how all three domains of L3 may function together as a ‘rocker switch’ to coordinate the stepwise processes of translation elongation.