2,261 research outputs found
Efficient Transport Protocol for Networked Haptics Applications
The performance of haptic application is highly sensitive to communication delays and losses of data. It implies several constraints in developing networked haptic applications. This paper describes a new internet protocol called Efficient Transport Protocol (ETP), which aims at developing distributed interactive applications. TCP and UDP are transport protocols commonly used in any kind of networked communication, but they are not focused on real time application. This new protocol is focused on reducing roundtrip time (RTT) and inter packet gap (IPG). ETP is, therefore, optimized for interactive applications which are based on processes that are continuously exchanging data.ETP protocol is based on a state machine that decides the best strategies for optimizing RTT and IPG. Experiments have been carried out in order to compare this new protocol and UDP
Second phalanx shortening osteotomy. An innovative technique for long second toe syndrome
AbstractLong second-toe syndrome, although frequent and disabling, has been little described. Current surgical techniques often lead to loss of function. Based on anatomical and biomechanical observations, the present study reports a second phalanx shortening osteotomy technique. The procedure is relatively non-invasive, involving self-stabilizing segment resection osteotomy of the second phalanx. Results for the first 23 feet undergoing the procedure were analyzed retrospectively. Assessment comprised clinical examination, radiography and AOFAS and FAAM scores. Mean follow-up was 19±9.9months. Second phalanx shortening osteotomy proved reliable, respecting the biomechanics of the toe
Unimanual and Bimanual Weight Perception of Virtual Objects with a new Multi-finger Haptic Interface
Accurate weight perception is important particularly in tasks where the user has to apply vertical forces to ensure safe landing of a fragile object or precise penetration of a surface with a probe. Moreover, depending on physical properties of objects such as weight and size we may switch between unimanual and bimanual manipulation during a task. Research has shown that bimanual manipulation of real objects results in a misperception of their weight: they tend to feel lighter than similarly heavy objects which are handled with one hand only [8]. Effective simulation of bimanual manipulation with desktop haptic interfaces should be able to replicate this effect of bimanual manipulation on weight perception. Here, we present the MasterFinger-2, a new multi-finger haptic interface allowing bimanual manipulation of virtual objects with precision grip and we conduct weight discrimination experiments to evaluate its capacity to simulate unimanual and bimanual weight. We found that the bimanual ‘lighter’ bias is also observed with the MasterFinger-2 but the sensitivity to changes of virtual weights deteriorated
Using diffusion tensor imaging to identify corticospinal tract projection patterns in children with unilateral spastic cerebral palsy.
AIM: To determine whether diffusion tensor imaging (DTI) can be an independent assessment for identifying the corticospinal tract (CST) projecting from the more-affected motor cortex in children with unilateral spastic cerebral palsy (CP). METHOD: Twenty children with unilateral spastic CP participated in this study (16 males, four females; mean age 9y 2mo [standard deviation (SD) 3y 2mo], Manual Ability Classification System [MACS] level I-III). We used DTI tractography to reconstruct the CST projecting from the more-affected motor cortex. We mapped the motor representation of the more-affected hand by stimulating the more- and the less-affected motor cortex measured with single-pulse transcranial magnetic stimulation (TMS). We then verified the presence or absence of the contralateral CST by comparing the TMS map and DTI tractography. Fisher's exact test was used to determine the association between findings of TMS and DTI. RESULTS: DTI tractography successfully identified the CST controlling the more-affected hand (sensitivity=82%, specificity=78%). INTERPRETATION: Contralateral CST projecting from the lesioned motor cortex assessed by DTI is consistent with findings of TMS mapping. Since CST connectivity may be predictive of response to certain upper extremity treatments, DTI-identified CST connectivity may potentially be valuable for determining such connectivity where TMS is unavailable or inadvisable for children with seizures.K08 NS073796 - NINDS NIH HHS; TL1 RR024158 - NCRR NIH HHS; K01 NS062116 - NINDS NIH HHS; UL1 RR024156 - NCRR NIH HHS; KL2 RR024157 - NCRR NIH HHS; R01 HD076436 - NICHD NIH HHSPublished versio
First-principles elucidation of the surface chemistry of the C2Hx (x = 0–6) adsorbate series on Fe(100)
Ab initio total-energy calculations of the elementary reaction steps leading to acetylene, ethylene and ethane formation and their decomposition on Fe(100) are described. Alongside the endothermicity of all the formation reactions, the crucial role played by adsorbed ethyl as main precursor towards both ethylene and ethane formation, characterises Fe(100) surface reactivity towards C2Hx (x = 0–6) hydrocarbon formation in the low coverage limit. A comprehensive scheme based on three viable mechanisms towards ethyl formation on Fe(100), including methyl/methylene coupling, methyl/methylidyne coupling followed by one hydrogenation and methyl/carbon coupling followed by two hydrogenations, is the main result of this article
Ethanol Electro-oxidation Reaction Selectivity on Platinum in Aqueous Media
Ethanol fuel cells require selective catalysts for complete oxidation of the fuel, which involves C–C bond cleavage. From experiments on well-defined surfaces and calculations, the mechanism controlling the ethanol electro-oxidation selectivity on platinum in aqueous media as a model system is elucidated. Adsorbed OH favors ethanol adsorption and conversion into adsorbed ethoxy, which favorably evolves to adsorbed COCH3. On Pt(111), adsorbed OH is also readily incorporated into adsorbed COCH3 to yield acetic acid. A higher barrier for this latter step on Pt(100) enables the COCH3 dehydrogenation to adsorbed COCH2, favoring C–C bond cleavage. As adsorbed OH plays an essential role as a reactant in this process, its adsorption properties have a decisive impact on this reaction. Furthermore, the adsorbed OH diffusion rate on the surface, which depends on the adsorbate/media/surface interaction at the interface, modulates the availability of this key reactant. These results highlight that the search for selective electrocatalysts requires holistic consideration of reactants, adsorbates, media, and substrate.This research was funded by Ministerio de Ciencia e Innovación (Spain) grant nos. PID2019-105653GB-I00 and FJC2018-038607-I and Generalitat Valenciana (Spain) grant no. PROMETEO/2020/063
Glutamate adsorption on the Au(111) surface at different pH values
Adsorbed amino acids can modulate the behavior of metal nanoparticles in advanced applications. Using a combination of electrochemical experiments, FTIR spectroscopy, and DFT calculations, glutamate species interacting with the Au(111) surface in solution are here investigated. Electrochemical results indicate that the adsorption behavior depends on the solution pH (which controls the glutamate ionization) and on the charge of the surface. Glutamate adsorption starts at potentials slightly negative to the potential of zero charge. The thermodynamic analysis of these results indicates that two electrons are exchanged per molecule, implying that both carboxylic groups become deprotonated upon adsorption. The FTIR spectra reveal that carboxylate groups are bonded to the surface in the bidentate configuration (with both oxygen atoms attached to the surface). Plausible adsorbed configurations, consistent with the whole of these insights, were found using DFT. -Additionally, it was observed that glutamate oxidation only takes place when the surface is oxidized, which suggests that this oxidation process involves the transfer of an oxygen group to the molecule, though, according to the FTIR spectra, the main chain remains intact.Financial support from Ministerio de Ciencia e Innovación (Project PID2019-105653GB-100) and Generalitat Valenciana (Project PROMETEO/2020/063) is acknowledged
Shared binding sites for the Bacillus thuringiensis proteins Cry3Bb, Cry3Ca and Cry7Aa in the African sweetpotato pest Cylas puncticollis (Brentidae).
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