Preparative isopycnic density-gradient centrifugation is ordinarily done in high-speed swinging-bucket rotors such as the Spinco SW 39 and SW 25. In addition to requiring this special equipment, the technique is severely limited by the small number of samples and the low total-sample volume which may be used. In recent studies on methods for isolating small numbers of virus particles from tissu...

Methods We compared co-occurrence-based distributions of habitat specialization of tree species in two geographic regions that are ecologically similar but differ in species pool size. We applied two methods. First, we used a rank-ordering of species along a gradient of estimated niche breadth that is based solely on species co-occurrence information derived from vegetation databases from each ...

In this paper we investigate extending the gradient-based inverse compositional image alignment method described by Baker and Matthews [1] by formulating the alignment process probabilistically using Bayes rule to obtain a posterior estimate of the alignment. The probabilistic formulation makes use of prior statistical information on the aligning function parameters, and we investigate the use ...

Friction welding or electron/laser beam of nickel superalloys compromises the microstructure with localized melting and heat-affected zones (HAZ). In this work, Field-Assisted Sintering Technology (FAST) is studied as an alternative method for solid-state diffusion bonding CM247LC Inconel 718. Bonding microstructures room-temperature tensile strengths are evaluated. Preliminary results suggest ...

Simpson’s paradox, also known as amalgamation or aggregation paradox, appears when dealing with proportions. Proportions are by construction parts of a whole, which can be interpreted as compositions assuming they only carry relative information. The Aitchison inner product space structure of the simplex, the sample space of compositions, explains the appearance of the paradox, given that amalg...

This paper is motivated by the recent interest in the analysis of high dimensional microbiome data. A key feature of this data is the presence of ‘structural zeros’ which are microbes missing from an observation vector due to an underlying biological process and not due to error in measurement. Typical notions of missingness are insufficient to model these structural zeros. We define a general ...