Dexterity

A new three Degree Of Freedom (3-DOF) parallel manipulator has been proposed in this study. Because the parallel manipulator has three Degree Of Freedom (DOF), one translation degree of freedom and two rotational degrees of freedom, it has received considerable attention from both researchers and manufacturers over the past years. The inverse kinematic and Jacobain matrix were derived. The dexterity of the parallel manipulator is presented. The key issue of how the kinematic performance in term of dexterity varies with differences in the structural parameters of the parallel manipulator is investigated. The simulation results, using MATLAB, testify the validity of the analytic model and illustrate the structural parameters have direct effect upon dexterity characteristic of the 3-DOF parallel manipulator.

Background: Cerebellar and motor tracts are frequently impaired in multiple sclerosis (MS). Altered hand dexterity constitutes a challenge in clinical practice, since medical treatment shows very limited benefits in this domain. Cerebellar control is made via several cerebellocortical pathways, of which the most studied one links the cerebellum to the contralateral motor cortex via the contralateral ventro-intermediate nucleus of the thalamus influencing the corticospinal outputs. Modulating the activity of the cerebellum or of the motor cortex could be of help. Method: The main interest here is to evaluate the efficacy of transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique, in treating altered dexterity in MS. Forty-eight patients will be recruited in a randomized, double-blind, sham-controlled, and crossover study. They will randomly undergo one of the three interventions: anodal tDCS over the primary motor area, cathodal tDCS over the cerebellum, or sham. Each block consists of five consecutive daily sessions with direct current (2 mA), lasting 20 min each. The primary outcome will be the improvement in manual dexterity according to the change in the time required to complete the nine-hole pegboard task. Secondary outcomes will include fatigue, pain, spasticity, and mood. Patients' safety and satisfaction will be rated. Discussion: Due to its cost-effective, safe, and easy-to-use profile, motor or cerebellar tDCS may constitute a potential tool that might improve dexterity in MS patients and therefore ameliorate their quality of life.

This paper discusses the importance of covertly repeated practice rather than overt repetition in learning, especially extensive reading for learning English as a foreign language at school. Covertly repeated practice will enable the learners to focus on being involved in the tasks while overtly repeated practice may automatize the target expressions but they may not be able to use the expressions in different contexts. Extensive reading is considered to offer covertly repeated practice to the learners properly and to be one of the ideal methods for the learners to acquire an adequate command of English.

While theory may constitute the fundamental starting point, giving students a general culture specific for their careers, the fact is that they must acquire the skills, techniques, and analytical tools for very specific situations, and internships are one of the most important means to acquire these skills, which will allow them, in the future, to operate with self-assurance and expertise in their field. Their professional performance will be evaluated by their practical skills, bearing in mind that this is a world of results.
Resumen:
Si bien la teoría puede llegar a constituir el punto de partida fundamental, que aporta una cultura general especifica al estudiante, lo cierto es que éste debe adquirir destrezas, técnicas, habilidades y análisis a situaciones muy concretas, y la práctica empresarial es uno de los medios más importantes para adquirir estas competencias, que le permitirán en un futuro, desenvolverse con seguridad e idoneidad en su campo profesional. Su desenvolvimiento profesional será evaluado por sus habilidades prácticas; hay que tener en cuenta que este es un mundo de resultados.