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The present study introduces sparse modeling for the estimation of propagation patterns in intracardiac atrial fibrillation (AF) signals. The estimation is based on the partial directed coherence (PDC) function, derived from fitting a multivariate autoregressive model to the observed signals. A sparse optimization method is proposed for estimation of the model parameters, namely, the adaptive grou

Abstract in UndeterminedUsing an exact circuit analogy for the scattering ofvector spherical waves, it is shown how the problem of determiningthe optimal scattering bounds for a homogeneous spherein its high-contrast limit is identical to the closely related, andyet very different problem of finding the broadband tuning limitsof the spherical waves. Using integral relations similar to Fano’sbroadb

A sum rule valid for a large class of linear and reciprocal antennas is presented in terms of the electric and magnetic polarizability dyadics. The identity is based on the holomorphic properties of the forward scattering dyadic and includes arbitrarily shaped antennas modelled by linear and time-translational invariant constitutive relations. In particular, a priori estimates on the partial reali

Cardiovascular risk increases with chronological as well as biological aging, and one marker of this might be telomere length. The telomere cap is located at the end of the DNA helix and serves to protect its end. This is an evolutionary adaptation which has resulted in stabilization of the DNA strand within the chromosome. During the life course, telomeres tend to shorten in most cells, with the

A common assessment of postural control often involves subjects standing on a compliant surface, such as a foam block, to make balance tests more challenging. However, the physical properties of the foam block used by different researchers can vary considerably. The objective of this study was to provide an initial approach for investigating whether two of the foam properties, i.e. density and ela

Popular Abstract in Swedish Den kroniska inflammation som ses hos personer med inflammatorisk tarmsjukdom är troligen en immunologisk reaktion riktad mot normala tarmbakterier. I denna process har monocyter/makrofager (särskild celltyp av vita blodkroppar) en central betydelse. Det är huvudsakligen makrofager i tarmslemhinnan som styr det immunsvar som utvecklas då tarmfloran kommer i kontakt med Inflammatory bowel disease is thought to result from the inappropriate and ongoing activation of the mucosal immune system driven by the presence of normal luminal flora. In this process monocytes/macrophages contribute to and maintain chronic inflammation by being both regulatory and effector cells. This study aimed at exploring the effects and regulation of chronic inflammation in inflammatory

A box graph is the intersection graph of a finite set of orthogonal rectangles in the plane. The problem of whether or not the maximum independent set problem (MIS for short) for box graphs can be approximated within a substantially sub-logarithmic factor in polynomial time has been open for several years. We show that for box graphs on n vertices which have an independent set of size Ω(n/logO(1)n

Despite growing interest on the potential use of de-cellularized whole lungs as 3-dimensional scaffolds for ex vivo lung tissue generation, optimal processing including sterilization and storage conditions, are not well defined. Further, it is unclear whether lungs need to be obtained immediately or may be usable even if harvested several days post-mortem, a situation mimicking potential procureme

All fluorine atoms in fluoride compounds discussed in this book were synthesized in the stars or in stellar processes well before the solar system was formed some 4.6. billion years ago. The main cosmic production sites are, however, still elusive. This is not only because it is challenging to empirically determine the buildup of fluorine abundance in the universe over time, but also because of th