An incremental, nonparametric probability estimation procedure using the fuzzy ARTMAP (adaptive resonance theory-supervised predictive mapping) neural network is introduced. In the slow-learning mode, fuzzy ARTMAP searches for patterns of data on which to build ever more accurate estimates. In max-nodes mode, the network initially learns a fixed number of categories, and weights are then adjust...

The intergalactic medium was not completely reionized until approximately a billion years after the Big Bang, as revealed by observations of quasars with redshifts of less than 6.5. It has been difficult to probe to higher redshifts, however, because quasars have historically been identified in optical surveys, which are insensitive to sources at redshifts exceeding 6.5. Here we report observat...

We argue that the stochastic dynamics of interacting agents which replicate, mutate and die constitutes a non-equilibrium physical process akin to aging in complex materials. Specifically, our study uses extensive computer simulations of the Tangled Nature Model (TNM) of biological evolution to show that punctuated equilibria successively generated by the model’s dynamics have increasing entrop...

Leishmania major, an intracellular parasitic protozoon that infects, differentiates and replicates within macrophages, encodes two closely related MIF-like proteins, which have only ~20% amino acid identity with mammalian MIF. Recombinant L. major MIF1 and MIF2 have been expressed and the structures, resolved by X-ray crystallography, show a trimeric ring architecture similar to mammalian MIF b...

Try to imagine a fast biological movement. Perhaps you visualize the twitch of an eye or the flicker of a boxer’s jab. These movements may seem fast, but in this issue of Biophysical Journal, Upadhyaya and colleagues take biological speed to a whole new level by analyzing the contractions of Vorticella, a wineglass shaped ciliated protist (1). When a Vorticella cell is frightened, it can contra...

To investigate the role of jasmonate in the defense of plants against fungal pathogens, we have studied a mutant of Arabidopsis, fad3–2 fad7–2 fad8, that cannot accumulate jasmonate. Mutant plants were extremely susceptible to root rot caused by the fungal root pathogen Pythium mastophorum (Drechs.), even though neighboring wild-type plants were largely unaffected by this fungus. Application of...

References:1. Keller, et. al. (2011). The price of tenofovir-emtricitabine undermines the cost-effectiveness and advancement of pre-exposure prophylaxis. AIDS (London, England), 25(18), 10.1097/QAD.0b013e32834d3cab. http://doi.org/10.1097/QAD.0b013e32834d3cab 2. Impact studies: Mathematical models Cost-effectiveness studies. (n.d.). 3. Paltiel et. al. (2009). HIV Pre-exposure Prophylaxis (PrEP)...

Non linear sigma models on Riemannian symmetric spaces constitute the most general class of classical non linear sigma models which are known to be integrable. Using the the current algebra structure of these models their canonical structure is analysed and it is shown that their non ultralocal fundamental Poisson bracket relation is governed by a field dependent non antisymmetric r-matrix obey...

Spin-flip and non-spin-flip mechanisms have been proposed to explain polarization asymmetry in inelastic electron scattering from iron and nickel. A maximum in the asymmetry near 2 eV in iron can occur by both mechanisms. The 300 meV maximum in nickel is unlikely to occur by non-spin-flip transitions. Spin-resolved electron-energy loss spectroscopy has been used to study electron-hole excitatio...

Seaweed cultivation is the fastest-growing aquaculture sector, with a demonstrable potential to drive development in some of poorest coastal populations worldwide. However, sustainable exploitation, fair access and equitable benefits from marine genetic resources, such as seaweeds have yet be fully realised. Patchy fundamental knowledge on diversity metabolic algae limits their exploitation; sc...