Currently I am working in biologically motivated problems.
1. I found and developed the
concept of a Physical Pseudoknot, which is a very stable localized
entanglement, which can be formed with high probability in helical
structures due to a mechanical ratchet mechanism.
2. Theoretical Immunology: I proposed a theory for explaining
how the immune systems discriminates self from nonself. This theory
uses a new concept: Cellular Frustration.
3. Evolutionary Biology: I proposed a robust theory to explain
the origin of species in sympatry. The theory we propose uses a new
mechanism that strongly amplifies selection. This mechanism is also
essential to explain self/nonself discrimination in the immune
system and it resembles a generalization of the kinetic proofreading
mechanism first proposed by Hopfield and Ninio.
4. Medical Physics and Rehabilitation: I am developing
instruments and theories to improve the rehabilitation of patients
with spinal cord injuries.
5. 3D Vision and Perception: I am trying to improve our ability
to see in 3D without the help of special glasses. I am also working
on a new task that highlights serial and parallel visual processing
6. Science Education and Communication: I planned and built some
experiments for FISICA VIVA 2005, a major event to brought physics
to the general public in the biggest shopping centers in Portugal.
Formerly I developed a renormalization group approach that I
applied to the theory of HTC superconductivity. These works showed
that nesting induces incipient SDW instabilities that are connected
to SC instabilities at lower temperatures. This could explain the
emergence of pseudogaps in HTCs. From these works I am led to think
that HTC superconductivity arises due to the existence of nesting in
some planes, and BCS instabilities in others (possibly induced by
phonons). The nesting induces the incipient AF observed in the
pseudogap phase, while it also increases the SC critical temperature
due to the coupling of BCS processes within both types of planes.
Abreu, F.V., Nolte-´Hoen, E.N.M., Almeida, C.R. and Davis, D.M.,
Cellular Frustration: a New Conceptual Framework for Understanding
Cell-Mediated Immune Responses (2006) LNCS 4163, 37-51, [pdf]
Almeida, C.R. and de Abreu, F.V., Dynamical instabilities lead to
sympatric speciation. Evol.Ec. Res. (2003) 5: 739-757,
Nesting induced precursor effects: A renormalization group approach,
de Abreu F.V., Doucot B. Phys. Rev. Lett. 86 (13): 2866-2869 MAR 26