Visuomotor processing and hand force coordination in dyslexic children during a visually guided manipulation task

Developmental Dyslexia negatively affects children's reading and writing ability and, in most cases, performance in sensorimotor tasks. These deficits have been associated with structural and functional alterations in the cerebellum and the posterior parietal cortex (PPC). Both neural structures are active during visually guided force control and in the coordination of load force (LF) and grip force (GF) during manipulation tasks. Surprisingly, both phenomena have not been investigated in dyslexic children. Therefore, the aim of this study was to compare dyslexic and non-dyslexic children regarding their visuomotor processing ability and GF-LF coordination during a static manipulation task. Thirteen dyslexic (8-14YO) and 13 age- and sex-matched non-dyslexic (control) children participated in the study. They were asked to grasp a fixed instrumented handle using the tip of all digits and pull the handle upward exerting isometric force to match a ramp-and-hold force profile displayed in a computer monitor. Task performance (i.e., visuomotor coordination) was assessed by RMSE calculated in both ramp and hold phases. GF-LF coordination was assessed by the ratio between GF and LF (GF/LF) calculated at both phases and the maximum value of a cross-correlation function (r(max)) and its respective time lag calculated at ramp phase. The results revealed that the RMSE at both phases was larger in dyslexic than in control children. However, we found that GF/LF, rmax, and time lags were similar between groups. Those findings indicate that dyslexic children have a mild deficit in visuomotor processing but preserved GF-LF coordination. Altogether, these findings suggested that dyslexic children could present mild structural and functional alterations in specific PPC or cerebellum areas that are directly related to visuomotor processing. (C) 2014 Elsevier Ltd. All rights reserved.

Kraftutveckling för manuella trädfällningsredskap : Force development for manual tree felling tools

The objective with this study has been to build general models of the mechanics in tree felling with chain-saw and to compare felling torque for different tools. The theoretical models are completed and validated with a comparative study. The study includes a great number of felling tools of which some are used with different methods. Felling torque was measured using a naturally like measuring arrangement where a tree is cut at about 3.7 m height and then anchored with a dynamometer to a tree opposite to the felling direction. Notch and felling cut was made as ordinary with exception that the hinge was made extra thin to reduce bending resistance. The tree was consequently not felled during the trials and several combinations of felling tools and individuals could be used on the same tree.The results show big differences between tools, methods and persons. The differences were, however, not general, but could vary depending on conditions (first of all tree diameters). Tools and methods that push or pull on the stem are little affected by the size of the tree, while tools that press on the stump are very much dependent of a large stump-diameter. Hand force asserted on a simple pole is consequently a powerful tool on small trees. For trees of medium size there are several alternative methods with different sizes and brands of felling levers and wedges. Larger and more ungainly tools and methods like tree pusher, winch, etc. develop very high felling torque on all tree sizes. On large trees also the felling wedge and especially the use of several wedges together develop very high felling torque.

Dinamômetro biomédico para avaliação funcional das mãos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Injustiça e poder segundo Noam Chomsky

Injustice and power according to Noam Chomsky. In the beginning of the Politics, Aristotle establishes the two lesser forms of sociability: the relationships between man and woman and between master and the slave. In this context, he observes that “Hellenes are natural masters of barbarians” and the reason is that Greeks know philosophy and barbarians still resort to violence (ARISTOTLE, Politics, 1252a.). Shortly after defines “just war” as a war that has a fair cause, that is, which is well justified by philosophy or a fair speech (ARISTOTLE, Politics, 1255a.). This scene briefly expresses the manner in which the USA understands their role in the contemporary world. Chomsky points out the political use of massive military force of his country and denounces how it articulates internally and externally. He affirms that politics is excessively submitted to “ideology”, to doxa, as opposed to natural sciences. His militancy, thus, only advocates freedom and unrestricted right to information. In Camelot, the Kennedy years (1993), for example, the MIT’s professor collects information from congressmen’s speeches and government officials and from secret documents made public and he explicits the methods and actions of the US government. Thereby he can conclude that the US has, for historical reasons, an internal posture that is advocate or contrary to what they imposes to other countries. Power and justice on the one hand, force and injustice on the other –according to their own political discourse.

Estudo, desenvolvimento e concepção de uma célula de carga

In engineering projects, it’s fundamental to determine the active loads in components in order to guarantee acceptable values of safety and reliability according to project specifications. On the other hand, force measurement methods might be very complex and impracticable in some cases and, so that, load cells with eletric resistance strain gages can be applied as a simple and accurate option to measure the required load. The main purpose of this paper is to present the development of a load cell that measures uniaxial forces using electric resistance strain gages without being influenced by the location of the loading in a cantilever beam. For that, it was taken as basis a secondary purpose which is to present a general study of basic and wide concepts about transducers, load cells and extensometers primarily. Information such as: loading and measurements types, characteristics of the presented devices as well as factors that influence its functioning, the most common kinds of Wheatstone bridge links, the main points of a load cell project, cements used to fix extensometers and, finally, the project itself with the tests of the built transducer are presented. By the end of this paper, all the results are shown and analyzed, concluding about the designed load cell and the work itself

Az e-business kooperatív turisztikai adaptációja : "A kicsi, a szép esélyei hazánkban" (The cooperative touristy adoption of e-business: "The chances of small beautiful in Hungary")

A cikk legfontosabb megválaszolandó kérdése: Milyen esélyekkel és milyen szükséges lépésekkel indulhatnak a nemzetközileg kevéssé ismert hazai célállomások és vállalkozásaik a turisztikai piac globális versenyében, melynek egyre jelentősebb színterét az internet adja? A turisztikai piacon az internet piacalakító hatása és az individualista, élmény, és értékközpontú kereslet megjelenése olyan változásokat indított el az elmúlt közel húsz évben, melyek befolyásolva a szereplők erőviszonyait a fejlődés lehetőségét hordozzák a regionális célállomások, a kevéssé ismert desztinációk számára. Mindezen trendek egyúttal kihívást jelentenek, mivel élesítik a versenyt, és megújulásra ösztönzik a globálisan ismert desztinációkat is, valamint számos nehézség megoldására késztetik a több szempontból hátrányban szenvedő vidéki régiókat. A cikkben ismertetendő kutatás célja az, hogy egy best practice-ként ismert osztrák és három hazai eset alapján felderítse azon tényezőket, melyek a desztinációfejlesztés kezdeti lépésétől az e-business sikeres adaptációjához, a desztinációmenedzsment-rendszerek bevezetéséhez és működtetéséhez vezetnek. __________ The main question of the paper: What kind of steps should the Hungarian less-known destinations take to meet the challenges of the global competition increasingly taking place on the internet? The trends of “new tourism” – driven by post-materialistic values –, and the growing role of internet in touristy activity have formed new conditions and changed the balance of forces in the touristy market. These two trends hand in hand have intensified the competition: on the one hand force global destinations to renew, on the other hand give great but challenging possibilities for regional destinations in comparative disadvantage. The aim of the paper is to identify the success-factors of adopting e-business solution called destination management system in the regional, undeveloped areas starting destination management from zero position. For this purpose case studies were examined by analyzing Hungarian regional destinations’ development and making a benchmark analysis through an Austrian best practice.

Force distribution in manipulation by a robot hand with equality and inequality constraints

The problem of the appropriate distribution of forces among the fingers of a four-fingered robot hand is addressed. The finger-object interactions are modelled as point frictional contacts, hence the system is indeterminate and an optimal solution is required for controlling forces acting on an object. A fast and efficient method for computing the grasping and manipulation forces is presented, where computation has been based on using the true model of the nonlinear frictional cone of contact. Results are compared with previously employed methods of linearizing the cone constraints and minimizing the internal forces.

A hand book for infantry: containing the first principles of military discipline, founded on rational method: intended to explain in a familiar and practical manner, for the use of the military force of the United States, the modern improvements in the discipline and movement of armies.

Half-title: Regulations to be received and observed for the discipline of infantry in the army of the United States.

Do synergies improve accuracy? A study of speed-accuracy trade-offs during finger force production

We explored possible effects of negative covariation among finger forces in multifinger accurate force production tasks on the classical Fitts's speed-accuracy trade-off. Healthy subjects performed cyclic force changes between pairs of targets ""as quickly and accurately as possible."" Tasks with two force amplitudes and six ratics of force amplitude to target size were performed by each of the four fingers of the right hand and four finger combinations. There was a close to linear relation between movement time and the log-transformed ratio of target amplitude to target size across all finger combinations. There was a close to linear relation between standard deviation of force amplitude and movement time. There were no differences between the performance of either of the two ""radial"" fingers (index and middle) and the multifinger tasks. The ""ulnar"" fingers (little and ring) showed higher indices of variability and longer movement times as compared with both ""radial"" fingers and multifinger combinations. We conclude that potential effects of the negative covariation and also of the task-sharing across a set of fingers are counterbalanced by an increase in individual finger force variability in multifinger tasks as compared with single-finger tasks. The results speak in favor of a feed-forward model of multifinger synergies. They corroborate a hypothesis that multifinger synergies are created not to improve overall accuracy, but to allow the system larger flexibility, for example to deal with unexpected perturbations and concomitant tasks.

Peak force in familial amyloidotic polyneuropathy

Familial Amyloidotic Polyneuropathy FAP)- A neurodegenerative disease related with systemic deposition of amyloid fibers mainly at the level of the peripheral nervous system. Clinically, the disease is characterized by an autonomous sensitive-motor neuropathy, beginning nearly always in foot, and subsequently involving the hands. Purpose: Compare the levels of hand grip strength (peak force) in FAP patients with (FAPT) or without (FAPNT) liver transplant and in a healthy group (HG).

Angular and linear accelerations of a rolling cylinder acted by an external force

The dynamics of a cylinder rolling on a horizontal plane acted on by an external force applied at an arbitrary angle is studied with emphasis on the directions of the acceleration of the centre-of-mass and the angular acceleration of the body. If rolling occurs without slipping, there is a relationship between the directions of these accelerations. If the linear acceleration points to the right, then the angular acceleration is clockwise. On the other hand, if it points to the left, then the angular acceleration is counterclockwise. In contrast, if rolling and slipping occurs, the direction of the linear acceleration does not determine the direction of the angular acceleration. For example, the linear acceleration may point to the right and the angular acceleration clockwise or counterclockwise depending on the external force orientation and point of application.

Conduction mechanisms and charge storage in Si-nanocrystals metal-oxide-semiconductor memory devices studied with conducting atomic force microscopy

In this work, we demonstrate that conductive atomic force microscopy (C-AFM) is a very powerful tool to investigate, at the nanoscale, metal-oxide-semiconductor structures with silicon nanocrystals (Si-nc) embedded in the gate oxide as memory devices. The high lateral resolution of this technique allows us to study extremely small areas ( ~ 300nm2) and, therefore, the electrical properties of a reduced number of Si-nc. C-AFM experiments have demonstrated that Si-nc enhance the gate oxide electrical conduction due to trap-assisted tunneling. On the other hand, Si-nc can act as trapping centers. The amount of charge stored in Si-nc has been estimated through the change induced in the barrier height measured from the I-V characteristics. The results show that only ~ 20% of the Si-nc are charged, demonstrating that the electrical behavior at the nanoscale is consistent with the macroscopic characterization.