Complementary action of chemical and electrical synapses to perception

Acknowledgements This study was possible by partial financial support from the following agencies: Fundação Araucária, EPSRC-EP/I032606/1, CNPq No. 441553/2014-1, CAPES No. 17656-12-5 and Science Without Borders Program— Process Nos. 17656125, 99999.010583/2013-00 and 245377/2012-3.Peer reviewedPostprin

Towards absolute calibration of optical tweezers

Aiming at absolute force calibration of optical tweezers, following a critical review of proposed theoretical models, we present and test the results of MDSA (Mie-Debye-Spherical Aberration) theory, an extension of a previous (MD) model, taking account of spherical aberration at the glass/water interface. This first-principles theory is formulated entirely in terms of experimentally accessible parameters (none adjustable). Careful experimental tests of the MDSA theory, undertaken at two laboratories, with very different setups, are described. A detailed description is given of the procedures employed to measure laser beam waist, local beam power at the transparent microspheres trapped by the tweezers, microsphere radius and the trap transverse stiffness, as a function of radius and height in the (inverted microscope) sample chamber. We find generally very good agreement with MDSA theory predictions, for a wide size range, from the Rayleigh domain to large radii, including the values most often employed in practice, and at different chamber heights, both with objective overfilling and underfilling. The results asymptotically approach geometrical optics in the mean over size intervals, as they should, and this already happens for size parameters not much larger than unity. MDSA predictions for the trapping threshold, position of stiffness peak, stiffness variation with height, multiple equilibrium points and `hopping' effects among them are verified. Remaining discrepancies are ascribed to focus degradation, possibly arising from objective aberrations in the infrared, not yet included in MDSA theory.Comment: 15 pages, 20 figure

Employability and Higher Education: The Case Study of ESTM Master's Degree

The labor market in this globalized world, based on new technologies, is constantly changing. In an increasingly demanding and dynamic world of human resources competences, young people have to focus on their training in order to enter in the labor market better prepared and thus contribute to the success of the entity that receives them and for their own professional and personal fulfillment. The choice of their academic journey is crucial to ensure the achievement of these competences and make that decision is not easy, with a system of higher education such as the Portuguese, where there are so many graduation courses and two systems of teaching, University and Polytechnic. In fact, with the changes introduced in higher education by the so-called Bologna Process, most undergraduate’s courses saw the number of years reduced from five to three years, while others opted for integrated master's degrees. In the case of the School of Tourism and Maritime Technology, the option was to offer three-year degree courses and two-year master's degrees. This study intends to understand where are the students who have bet on their training at the master's level and finish their master's degree at the School of Tourism and Maritime Technology (ESTM) of the Polytechnic of Leiria, if they are working in the area and if the employers recognize these qualifications.info:eu-repo/semantics/publishedVersio

Infinitely Many Stochastically Stable Attractors

Let f be a diffeomorphism of a compact finite dimensional boundaryless manifold M exhibiting infinitely many coexisting attractors. Assume that each attractor supports a stochastically stable probability measure and that the union of the basins of attraction of each attractor covers Lebesgue almost all points of M. We prove that the time averages of almost all orbits under random perturbations are given by a finite number of probability measures. Moreover these probability measures are close to the probability measures supported by the attractors when the perturbations are close to the original map f.Comment: 14 pages, 2 figure

Área de refúgio é necessária?

bitstream/item/45894/1/Area-refugio.pd