PURPOSE Multiexponential decay parameters are estimated from diffusion-weighted-imaging that generally have inherently low signal-to-noise ratio and non-normal noise distributions, especially at high b-values. Conventional nonlinear regression algorithms assume normally distributed noise, introducing bias into the calculated decay parameters and potentially affecting their ability to classify t...

In vivo measurements of the human brain tissue water signal decay with b-factor over an extended b-factor range up to 6,000 s/mm(2) reveal a nonmonoexponential decay behavior for both gray and white matter. Biexponential parametrization of the decay curves from cortical gray (CG) and white matter voxels from the internal capsule (IC) of healthy adult volunteers describes the decay process and s...

Applying asymptotic expansions at threshold, we compute the two-loop QCD correction to the short-distance coefficient that governs the leptonic decay ψ → l+l− of a S-wave quarkonium state and discuss its impact on the relation between the quarkonium non-relativistic wave function at the origin and the quarkonium decay constant in full QCD. PACS Nos.: 13.20.Gd, 12.38.Bx Quarkonium decays played ...

It is well-known that the spontaneous decay rates of emitting sources such as atoms or quantum wells can be largely modified in optical micro-cavities. − 4 Controlled spontaneous-emission plays a key role in a new generation of micro and nano-optical devices. Highperformance micro-cavity lasers, for instance, have been already experimentally demonstrated. 6 Spontaneous decay rates modifications...

Biomphalaria amazonica Paraense, 1996 was collected from a permanent pond in the outskirts of the Bolivian city of Santa Cruz. Identification of the collected specimens was made by comparison with the original description of the species and with topotypic material in the collection of Instituto Oswaldo Cruz. Phylogenetic analysis confirmed that these Bolivian specimens belong to B. amazonica.

The subject of cosmological hydrogen recombination has received much attention recently because of its importance to predictions for and cosmological constraints from cosmic microwave background observations. While the central role of the two-photon decay 2s! 1s has been recognized for many decades, high-precision calculations require us to consider two-photon decays from the higher states ns, ...

in this research, the decay resistance of bagasse-polypropylene composite has been evaluated. the scope of research was to assess the effect of different weight percentages of bagasse (40, 55 and 70%) and coupling agent, (mapp) maleic anhydride grafted polypropylene (0, 4 and 6%) on the fungal decay of the composite. astm d1413-99 modified test method was used to carry out the decay test, trame...