Mediante un estudio de caso enlaAsociación de Productores de Cultivos Bajo Medio Controlado (APROMECO), ubicada en Zarcero-Costa Rica,el artículo logra determinar que el crédito es un elemento esencial para que los medianos... more
Mediante un estudio de caso enlaAsociación de Productores de Cultivos Bajo Medio Controlado (APROMECO), ubicada en Zarcero-Costa Rica,el artículo logra determinar que el crédito es un elemento esencial para que los medianos y pequeños productores agrícolas logren acceder a tecnología depunta que les permita conectarse con los agentes externos, por ende formar parte de una cadena internacional; sin embargo,las políticas de crédito no son suficientes para garantizar el éxito de estos productores, ya que conectarse a una cadena global es solo el principio de un largo camino para los productores locales, los cuales deben encontrar junto con la institucionalidad pública del sector, estrategias necesarias paramantenerse dentro de la cadena.
Recent experiments have shown the possibility of using the brain electrical activity to directly control the movement of robots or prosthetic devices in real time. Such neuroprostheses can be invasive or non-invasive, depending on how the... more
Recent experiments have shown the possibility of using the brain electrical activity to directly control the movement of robots or prosthetic devices in real time. Such neuroprostheses can be invasive or non-invasive, depending on how the brain signals are recorded. In principle, invasive approaches will provide a more natural and flexible control of neuroprostheses, but their use in humans is debatable given the inherent medical risks. Non-invasive approaches mainly use scalp electroencephalogram (EEG) signals and their main disadvantage is that these signals represent the noisy spatiotemporal overlapping of activity arising from very diverse brain regions, i.e., a single scalp electrode picks up and mixes the temporal activity of myriads of neurons at very different brain areas. In order to combine the benefits of both approaches, we propose to rely on the non-invasive estimation of local field potentials (LFP) in the whole human brain from the scalp measured EEG data using a recently developed inverse solution (ELECTRA) to the EEG inverse problem. The goal of a linear inverse procedure is to de-convolve or un-mix the scalp signals attributing to each brain area its own temporal activity. To illustrate the advantage of this approach we compare, using an identical set of spectral features, classification of rapid voluntary finger self-tapping with left and right hands based on scalp EEG and non-invasively estimated LFP on two subjects using a different number of electrodes.
