2,585 research outputs found
Disruption of the developmental programme of Trypanosoma brucei by genetic ablation of TbZFP1, a differentiation-enriched CCCH protein
No full textThe regulation of differentiation is particularly important in microbial eukaryotes that inhabit multiple environments. The parasite Trypanosoma brucei is an extreme example of this, requiring exquisite gene regulation during transmission from mammals to the tsetse fly vector. Unusually, trypanosomes rely almost exclusively on post-transcriptional mechanisms for regulated gene expression. Hence, RNA binding proteins are potentially of great significance in controlling stage-regulated processes. We have previously identified TbZFP1 as a trypanosome molecule transiently enriched during differentiation to tsetse midgut procyclic forms. This small protein (101 amino acids) contains the unusual CCCH zinc finger, an RNA binding motif. Here, we show that genetic ablation of TbZFP1 compromises repositioning of the mitochondrial genome, a specific event in the strictly regulated differentiation programme. Despite this, other events that occur both before and after this remain intact. Significantly, this phenotype correlates with the TbZFP1 expression profile during differentiation. This is the first genetic disruption of a developmental regulator in T. brucei. It demonstrates that programmed events in parasite development can be uncoupled at the molecular level. It also further supports the importance of CCCH proteins in key aspects of trypanosome cell function
Tension strength capacity of finger joined beech lamellas
No full textBeech wood has high mechanical properties, therefore the production of high quality beech glulam beams is one of our main objectives. Finger joints with standard geometries and adhesives used for joining coniferous wood are not sufficient in terms of strength when gluing beech wood. A hybrid glulam beam was produced and tested in a standard four point bending test. The beam was produced from finger joined beech lamellas on the outer sides and finger joined spruce lamellas in the middle. The results from the bending test showed a lack of tensile strength of the finger joints of beech lamellas on the bottom middle part of the beam, where the rupture occurred. We prepared a numerical model of finger joined beech lamellas and simulations of tension tests, parallel to the lamella. We performed parametric studies with multiple variables referring to geometrical properties of finger joints and two different types of applied adhesives. The results showed a high influence of the finger joint geometrical parameters. Experimental tests on the tension strength of the finger joints were performed. Two finger joint lengths were tested, 10 and 20 millimetres. The results showed a clear influence of the finger joint geometry where highest strengths were obtained with longer and thinner fingers
Do rules control power? GATT articles and arrangements in the Uruguay Round
No full textMany complain and offer evidence that in recent years the GATT system has become more power-oriented, less stable, and less equitable. A concern to reverse this drift was one of the motives that brought the international community to agree to undertake the Uruguay Round. Rules control power, assumed the signers of the Punte del Este declaration, therefore elaborating and extending GATT rules would move the international community toward a fairer, more stable international trading system. Finger and Dhar contend that the opposite is true. Particularly in the 1980s, the elaboration and application of GATT rules has been an exercise in the application of economic and political power, not in its control. GATT rules, in theory, are there to limit national trade restrictions. Finger and Dhar contend that in fact things work the other way around: national practice comes first, and determines what the GATT rules mean. GATT's rules do not put limits on national practices, but provide international santion for these practices. Such rules are not part of the thereforelution but are part of the problem. Theirs is a situation-specific argument, say Finger and Dhar, not a generic one. Their target is not"rules", nor is it"GATT". Rather, it is the GATT rules.Rules of Origin,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Common Carriers Industry,Transport and Trade Logistics,Trade Policy
Interview im Trafo-Blog
No full textDer Trafo-Blog (Blog for transnational research) der Max Weber-Stiftung hat mich in der Reihe 5in10 interview: Fünf Fragen in (mehr als) 10 Minuten - zu meinem Projekt, meiner Erfahrung als Wissenschaftler im Ausland, meinen Prägungen: “Mehr als nur die Lust am Exotischen” – 5in10 mit Jürgen Finger Interview (German) by the Trafo-Blog (Blog for transnational research) of the Max Weber-Stiftung. 5in 10 - 5 questions in (more than) 10 minutes on my project, on experiences as a foreign researche..
Comparing the Active, Functional, and Passive Range of Motion of Finger Joints Using Dynamic Measurement
No full textStudies on finger kinematics, especially the range of motion (RoM) measurements, are essential to understand the use of finger joints and the pathology of related disease. Limited literatures compared the active RoM (A-RoM) of finger joints with either their functional RoM (F-RoM) or passive RoM (p-RoM) using different measuring protocols and tools. This study aims to provide an overall comparison including all three types of RoMs. We measured A-RoM, F-RoM, and P-RoM, using a dynamic measurement system. Our goal is to investigate the relationships among the three RoMs by comparing their extreme rotation angles. The results suggested that P-RoM was the largest motion range, and F-RoM can exceed their A-RoM. The F-RoM of distal-interphalangeal joints may rotated 8–20° more than their A-RoM, mainly during precise and power manipulations. Besides to A-RoM, knowledge of F-RoM and P-RoM are also important for a comprehensive understanding for clinical practice, and thus, to support the optimization and evaluation of treatment devices for finger joint, such as implant replacement.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Human-Centered DesignApplied Ergonomics and Desig
CamPressID: Optimizing Camera Configuration and Finger Pressure for Biometric Authentication
No full textTo protect sensitive information on smartphones, state-of-the-art (SoA) studies exploit the built-in camera to capture PPG signals from fingertips as a hard-to-forge biometric. However, those studies do not provide a comprehensive analysis to optimize the camera parameters and finger pressure, leading to distorted and unstable PPG signals that degrade the authentication performance. To overcome these limitations, we propose the CamPressID framework. First, we analyze various camera parameters and optimize their configuration to obtain PPG signals with a high signal-to-noise ratio. Second, we investigate different finger pressures to identify the best pressure for every subject, in order to avoid signal distortion. To evaluate the performance of CamPressID, we collect a diverse dataset with 58 subjects. Our evaluation results show that CamPressID can improve the average balanced accuracy (BAC) by 10%. Moreover, the BAC reaches 90%, which is similar to the accuracy reported in the SoA using a dedicated PPG sensor for authentication.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Embedded SystemsWeb Information System
SoftGlove: Finger Vibrotactile Feedback
No full textIn this report the finger vibrotactile subsystem of the SoftGlove wearable haptic feedback glove is discussed. This system is an upgrade over the vibrotactile feedback that the current SenseGlove haptic feedback glove provides. The designed system consists of a linear resonant actuator (LRA) on each finger, which is controlled by a dedicated LRA driver over I2C. To overcome addressing limitations of the drivers, an I2C switch is used to be able to communicate with each driver individually. The system is characterized both in terms of latency and vibration strength. The peak-to-peak vibration strength is measured to be 1.44 G and a 10 % to 90 % rise and fall time of 44 ms from rest to the maximum vibration strength. Furthermore, the system is integrated with the other subsystems of the SoftGlove on a PCB.SoftgloveElectrical Engineerin
Exploring solutions for finger tremor patients: Designing finger tremor suppression through passive wearable
No full textThis report presents an explorative study in finding solutions for finger tremor patients diagnosed with Essential Tremor (ET). Tremors restrict patients from performing delicate movements, creating difficulty in daily activities, such as drinking, writing, cooking or eating. Besides the challenges in performing tasks, social anxiety often occurs and negatively influences social life.Currently, solutions for people with tremors are limited. STIL recognized this need and designed an orthosis for people with wrist tremors. The solution from STIL is an orthosis called the BEAM. The BEAM mechanically suppresses the wrist flexion extension and forearm pronation-supination tremors. Evaluation of the current BEAM concluded that wrist tremors are successfully suppressed, but tremors situated mainly in the fingers need additional stabilization. This study aims to design a functional wearable that mechanically suppresses finger tremors.To better understand finger tremors, the project provides information on hand anatomy, the current market for finger wearables, and a video analysis of previous tests from STIL. The research found that there is limited knowledge about finger tremors and available wearables specifically designed for them. In user tests STIL saw many people with tremors also deal with a finger tremor, people can benefit from a finger wearable . In addition, the design scope research aimed to identify the specific needs and desires of people with finger tremors. The focus is on discovering a healthy and comfortable balance between freedom of movement and suppression of the fingers. The research conducted with three participant showed that the thumb, index, and middle fingers at the MCP (third joint from top of finger) and PIP (second joint from top of finger) joints need to be suppressed and that participants desire an inconspicuous and open design.The ideation phase exists out of multiple iterations. The basis of the ideation is a meeting with an expert in Emerging Materials, a morphological card, and brainstorming with the team of STIL. The basis concluded in four promising design directions, which could suppress the finger tremor: wires with springs, gel/air damping, elastic bands, and splints with different stiffnesses. Prototypes were built to research and test the four directions. Finally, the most interesting concepts are elastic bands and splints with different stiffness. The elastic bands give a counterforce to the fingers by pulling them backward. The silicone splints in a glove are made of silicone with spring steel which lies on the fingers. The working principle and ergonomics of the elastic bands and silicone splints have been validated in patient research. The results showed that the silicone splints were better in terms of performance and comfort, while the elastic bands were preferred in terms of design and adaptability. The final concept used the working principle of silicone splints. The final iteration focuses on appearance, ergonomics, usability, and connection to the BEAM.In conclusion, this report provides a foundation for STIL to further develop a wearable solution for people with finger tremors. The working principle of using silicone splints to suppress finger tremors is promising, but additional iterations are necessary.Integrated Product Design | Medisig
ThermoSurf: Thermal display technology for dynamic and multi-finger interactions
No full textThermal feedback has been proven to enhance user experience in human-machine interactions. Yet state-of-the-art thermal technology has focused on the single finger or palm in static contact, overlooking dynamic and multi-finger interactions. The underlying challenges include incompatible designs of conventional interfaces for providing salient thermal stimuli for such interactions and, thereby, a lack of knowledge on human thermal perception for relevant conditions. Here we present the ThermoSurf, a new thermal display technology that can deliver temperature patterns on a large interface suitable for dynamic and multi-finger interactions. We also investigate how user exploration affects the perception of the generated temperature distributions. Twenty-three human participants interacted with the device following three exploration conditions: static-single finger, dynamic-single finger, and static-multi finger. In these experiments, the individuals evaluated 15 temperature differences ranging from -7.5°C to +1.5°C with an initial temperature of 38°C. Our results showed that human sensitivity against thermal stimuli is significantly greater for static-single finger contact compared to the other tested conditions. In addition, this interaction type resulted in higher thermal discrimination thresholds than the ones reported in the literature. Our findings offer new perspectives on providing salient and consistent thermal feedback for future tactile interfaces.</p
Finger motion and contact by a second finger influence the tactile perception of electrovibration
No full textElectrovibration holds great potential for creating vivid and realistic haptic sensations on touchscreens. Ideally, a designer should be able to control what users feel independent of the number of fingers they use, the movements they make, and how hard they press. We sought to understand the perception and physics of such interactions by determining the smallest 125 Hz electrovibration voltage that 15 participants could reliably feel when performing four different touch interactions at two normal forces. The results proved for the first time that both finger motion and contact by a second finger significantly affect what the user feels. At a given voltage, a single moving finger experiences much larger fluctuating electrovibration forces than a single stationary finger, making electrovibration much easier to feel during interactions involving finger movement. Indeed, only about 30% of participants could detect the stimulus without motion. Part of this difference comes from the fact that relative motion greatly increases the electrical impedance between a finger and the screen, as shown via detailed measurements from one individual. By contrast, threshold-level electrovibration did not significantly affect the coefficient of kinetic friction in any conditions. These findings help lay the groundwork for delivering consistent haptic feedback via electrovibration.Human-Robot Interactio
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