2,778 research outputs found
Myelination and Isochronicity in Neural Networks
Our brain contains a multiplicity of neuronal networks. In many of these, information sent from presynaptic neurons travels through a variety of pathways of different distances, yet arrives at the postsynaptic cells at the same time. Such isochronicity is achieved either by changes in the conduction velocity of axons or by lengthening the axonal path to compensate for fast conduction. To regulate the conduction velocity, a change in the extent of myelination has recently been proposed in thalamocortical and other pathways. This is in addition to a change in the axonal diameter, a previously identified, more accepted mechanism. Thus, myelination is not a simple means of insulation or acceleration of impulse conduction, but it is rather an exquisite way of actively regulating the timing of communication among various neuronal connections with different length
How to optimize benefits and attract physiotherapists for a professional association in Portugal?
This thesis is part of a Consulting Project for APF - Associação Portuguesa de
Fisioterapeutas. This project guides APF with recommendations to support it relieving its
financial vulnerability and expanding its operations, as their ultimate goal is to become
the Authority which regulates the physiotherapy profession in Portugal. The project
concluded that APF was efficient on cost savings. However, several recommendations
were made, focused on the revenue and operational fields. Those opportunities in the
business model were identified thanks to the collection of data, which included surveys
from current and potential members, but also secondary research and theoretical literature.
As the majority of the revenues of APF arise from member fees, conferences and learning
clinics, the research was focused on clarifying that physiotherapists could materialize
returns by joining the Association and taking advantage from the services which are
offered.
Transforming APF into a “member-centered” organization would promote its
membership, which consequently would affect positively the revenues and create
economies of scale.
“When associations host their annual meeting, it provides members a great opportunity
for face-to-face leaning, networking with their colleagues and industry partners.”
Michael Gruenberg, 2015
This study concludes with several recommendations, which will enable APF to attract
more members and increase its chances to become the National authority for the
physiotherapy profession
Ultra-Wideband FSS-Based Antennas
As antennas are indispensable elements in wireless systems, it is necessary to provide UWB antennas suitable for UWB systems. The most proposed UWB antennas have omnidirectional radiation, which provides the wide coverage area that is highly demanded by many conventional UWB applications. However, directional radiation is more beneficial for other UWB applications and it may even be beneficial for the conventional UWB omnidirectional applications in some environments that contain many sources of interference and distorting objects, where the omnidirectional radiation leads to high interference and loss of power in undesirable directions. Consequently, an immense research has addressed the issue of realizing UWB planar antennas with unidirectional radiation characteristics. Basically, the main technique used to create unidirectional radiation patterns is employing cavity-baking reflectors to redirect the back radiation, hence increasing the gain of the radiators. In addition, these reflectors can decouple the mounted radiator from the surroundings that can damage its characteristics. Therefore, we suggest the employment of UWB reflectors to achieve UWB planar antennas with directional radiation. Our research for designing optimal UWB reflectors has led to the investigation in the field of frequency selective surfaces (FSSs), which are valuable structures and can be of great interest to a wide range of applications especially UWB applications. Subsequently, the main aim of this chapter is to give a review of the fundamental uses of FSSs in antenna engineering and the basic physical concepts that have been employed to serve the purpose of enhancing antennas’ performances using FSSs with a variety of features and characteristics. Furthermore, it is geared toward the presentation of our proposed UWB FSS-based antennas. First, we use basic FSSs such as the capacitive and its complementary inductive FSSs to design UWB reflectors that can serve improving and stabilizing the gain of UWB antennas. Thereafter, a proposed UWB single-layer FSS is used to serve the same purpose. Then, the FSS is integrated and designed together with UWB radiator, which resulted in lower profile along with good performance
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