A new family of Markov branching trees: the alpha-gamma model

We introduce a simple tree growth process that gives rise to a new two-parameter family of discrete fragmentation trees that extends Ford's alpha model to multifurcating trees and includes the trees obtained by uniform sampling from Duquesne and Le Gall's stable continuum random tree. We call these new trees the alpha-gamma trees. In this paper, we obtain their splitting rules, dislocation measures both in ranked order and in sized-biased order, and we study their limiting behaviour.Comment: 23 pages, 1 figur

Estimating the relative order of speciation or coalescence events on a given phylogeny

The reconstruction of large phylogenetic trees from data that violates clocklike evolution (or as a supertree constructed from any m input trees) raises a difficult question for biologists - how can one assign relative dates to the vertices of the tree? In this paper we investigate this problem, assuming a uniform distribution on the order of the inner vertices of the tree (which includes, but is more general than, the popular Yule distribution on trees). We derive fast algorithms for computing the probability that (i) any given vertex in the tree was the j--th speciation event (for each j), and (ii) any one given vertex is earlier in the tree than a second given vertex. We show how the first algorithm can be used to calculate the expected length of any given interior edge in any given tree that has been generated under either a constant-rate speciation model, or the coalescent model

Factors Affecting Foreign Investor Choice in Types of U.S. Real Estate

Using transaction level data, we present the first analysis of the way that foreign investors choose among different types of United States real estate. Our findings based on the conditional logit model analysis for the 1980-91 period are consistent with the hypothesis that foreign investors behave in a traditional profit maximizing, risk minimizing fashion. In choosing among investments in four major categories (apartment, office, retail and industrial) foreign investor choice is most sensitive to changes in capitalization rates, market activity and current rent levels.

Unexpected transformation of dissolved phenols to toxic dicarbonyls by hydroxyl radicals and UV light.

Water treatment systems frequently use strong oxidants or UV light to degrade chemicals that pose human health risks. Unfortunately, these treatments can result in the unintended transformation of organic contaminants into toxic products. We report an unexpected reaction through which exposure of phenolic compounds to hydroxyl radicals (•OH) or UV light results in the formation of toxic α,β-unsaturated enedials and oxoenals. We show that these transformation products damage proteins by reacting with lysine and cysteine moieties. We demonstrate that phenolic compounds react with •OH produced by the increasingly popular UV/hydrogen peroxide (H2O2) water treatment process or UV light to form toxic enedials and oxoenals. In addition to raising concerns about potential health risks of oxidative water treatment, our findings suggest the potential for formation of these toxic compounds in sunlit surface waters, atmospheric water, and living cells. For the latter, our findings may be particularly relevant to efforts to understand cellular damage caused by in vivo production of reactive oxygen species. In particular, we demonstrate that exposure of the amino acid tyrosine to •OH yields an electrophilic enedial product that undergoes cross-linking reaction with both lysine and cysteine residues

Attitude Change and Need for Cognition: Individual Differences in Perceptions of Groups

It was hypothesized that attitudes will become most polarized when individuals have an opportunity for thought about a group for which they “tune in” a well-developed schema that is consistent with initial information. This process should be greater for low need than high need for cognition thinkers. Participants were given different opportunities for thought about either freedom fighters or rebel insurgents. Initial information was either consistent or inconsistent with group descriptors. Participants completed the Need for Cognition Scale. These hypotheses were partially supported. Attitudes were more polarized when participants tuned in a schema that was consistent with initial information. Limitations of this investigation (e.g., no manipulation checks) and future directions (e.g., direct assessment of schemas) are discussed

Alien Registration- Ford, Daniel W. (Strong, Franklin County)

https://digitalmaine.com/alien_docs/19292/thumbnail.jp