Configuración teórica de la motivación de salud desde la teoría de la autodeterminación

El estudio de la motivación humana es un constructo altamente complejo y con una gran variabilidad de enfoques. La teoría de la autodeterminación (TAD) ha demostrado una relativa efectividad y consistencia en muchos aspectos relacionados con la salud, como por ejemplo el ejercicio físico, la alimentación, el sueño, el bienestar psicológico o el consumo de tabaco. Las investigaciones muestran que la motivación autodeterminada se corresponde con la motivación intrínseca y en cambio la motivación extrínseca y sus formas de regulación pueden corresponderse con comportamiento no autodeterminados, pudiendo llegar hasta la desmotivación. En este trabajo se formula una construcción teórica sobre este modelo, introduciendo la percepción de riesgo (PR) y la vulnerabilidad percibida (VP) como elementos que pueden variar el sentido final de la motivación e incluso mejorar alguna de sus regulaciones extrínsecas y la desmotivación. Una de las posibilidades teóricas que sugerimos para intentar neutralizar los tipos no autodeterminados es procurar aumentar la PR y la VP de la persona, ya que estando estas dos variables altas, la probabilidad de que la desmotivación aparezca se reduce significativamente, y las acciones forzadas de la regulación externa y la regulación introyectada pueden amortiguarse y aumentar la internalización lo que podría favorecer los comportamientos de salud.

Complex learning: the role of knowledge, intelligence, motivation and learning strategies

This work presents the main theories and models formulated with the purpose of offering a global overview on the acquisition of knowledge and skills involved in the initial development of expert competence. Setting from this background, we developed an empirical work whose main purpose is to define those factors in a complex learning situation such as chapter-sized in a knowledge-rich domain. The results obtained in a sample of Master students reveal that the several variables intervening, such as the qualitative organization of knowledge, intellectual ability, motivation, the deliberate use of strategies, and a rich learning environment, contribute in an independent way to provide an explanation for the acquired knowledge.

Efficient intrinsic spin relaxation in graphene due to flexural distortions

We propose an intrinsic spin scattering mechanism in graphene originated by the interplay of atomic spin-orbit interaction and the local curvature induced by flexural distortions of the atomic lattice. Starting from a multiorbital tight-binding Hamiltonian with spin-orbit coupling considered non-perturbatively, we derive an effective Hamiltonian for the spin scattering of the Dirac electrons due to flexural distortions. We compute the spin lifetime due to both flexural phonons and ripples and we find values in the 1-10 ns range at room temperature. The proposed mechanism dominates the spin relaxation in high mobility graphene samples and should also apply to other planar aromatic compounds.

Anisotropic intrinsic spin relaxation in graphene due to flexural distortions

We propose an intrinsic spin scattering mechanism in graphene originated by the interplay of atomic spin-orbit interaction and the local curvature induced by flexural distortions of the atomic lattice. Starting from a multiorbital tight-binding Hamiltonian with spin-orbit coupling considered nonperturbatively, we derive an effective Hamiltonian for the spin scattering of the Dirac electrons due to flexural distortions. We compute the spin lifetime due to both flexural phonons and ripples and we find values in the microsecond range at room temperature. Interestingly, this mechanism is anisotropic on two counts. First, the relaxation rate is different for off-plane and in-plane spin quantization axis. Second, the spin relaxation rate depends on the angle formed by the crystal momentum with the carbon-carbon bond. In addition, the spin lifetime is also valley dependent. The proposed mechanism sets an upper limit for spin lifetimes in graphene and will be relevant when samples of high quality can be fabricated free of extrinsic sources of spin relaxation.

Intrinsic spin noise in MgO magnetic tunnel junctions

We consider two intrinsic sources of noise in ultra-sensitive magnetic field sensors based on MgO magnetic tunnel junctions, coming both from 25 Mg nuclear spins (I = 5/2, 10% natural abundance) and S = 1 Mg-vacancies. While nuclear spins induce noise peaked in the MHz frequency range, the vacancies noise peaks in the GHz range. We find that the nuclear noise in submicron devices has a similar magnitude than the 1/f noise, while the vacancy-induced noise dominates in the GHz range. Interestingly, the noise spectrum under a finite magnetic field gradient may provide spatial information about the spins in the MgO layer.