Rod-like Polyelectrolytes in Presence of Monovalent Salt

We investigate the properties of rigid polyelectrolyte solutions in presence of monovalent salt. The free energy within the Debye-H\"uckel-Bjerrum (DHBj) theory [M. E. Fisher and Y. Levin, {\it Phys. Rev. Lett.} 71, 3826 (1993)] is constructed. It is found that at thermodynamic equilibrium the polyelectrolyte solution consists of clusters composed of one polyion and various counterions. The distribution of the cluster densities is determined by finding the minimum of the Helmholtz free energy. The osmotic pressure and the average charge of the cluster are found and their dependence on Manning parameter $\xi$ is elucidated. A good agreement with the experimental results is obtained.Comment: 11 pages, Revtex (using twocolumn style), 15 figures and postscript file. Submitted to Macromomelecule

Coparenting in Fragile Families

Nonmarital childbearing has increased dramatically in the U.S. since the early 1960s, rising from 6% of all births in 1960 to fully 40% in 2007 (Hamilton, Martin, & Ventura, 2009). Whereas similar trends have occurred in many developed nations, the U.S. stands out in the extent to which such births are associated with socioeconomic disadvantage and relationship instability. This has given rise to a new term ‘fragile families,’ which we define as unmarried couples who have a child together. The increase in fragile families reflects changes not only in the initial context of births but also in the fundamental nature and patterns of childrearing.Fragile families, childbearing, nonmarital childbearing

Fathers in Fragile Families

Nonmarital childbearing has increased dramatically in the U.S. since the early 1960s, rising from 6% of all births in 1960 to fully 40% in 2007 (Hamilton, Martin, & Ventura, 2009; Ventura & Bachrach, 2000). Whereas similar trends have occurred in many developed nations, the U.S. stands out in the extent to which such births are associated with socioeconomic disadvantage and relationship instability, giving rise to a new term ‘fragile families.’ The increase in fragile families reflects changes not only in the context of births but also in the fundamental nature and patterns of childrearing, particularly with respect to fathers’ roles and involvement with children.Fragile families, childbearing, nonmarital childbearing, fartherhood, fathers

Liquid Polymorphism and Density Anomaly in a Lattice Gas Model

We present a simple model for an associating liquid in which polymorphism and density anomaly are connected. Our model combines a two dimensional lattice gas with particles interacting through a soft core potential and orientational degrees of freedom represented through thermal \char`\"{}ice variables\char`\"{} . The competition between the directional attractive forces and the soft core potential leads to a phase diagram in which two liquid phases and a density anomaly are present. The coexistence line between the low density liquid and the high density liquid has a positive slope contradicting the surmise that the presence of a density anomaly implies that the high density liquid is more entropic than the low density liquid

Amphiphile Adsorption on Rigid Polyelectrolytes

A theory is presented which quantitatively accounts for the cooperative adsorption of cationic surfactants to anionic polyelectrolytes. For high salt concentration we find that the critical adsorption concentration (CAC) is a bilinear function of the polyion monomer and salt concentrations, with the coefficients dependent only on the type of surfactant used. The results presented in the paper might be useful for designing more efficient gene delivery systems

HAWAII LONGLINE VESSEL ECONOMICS

Public Economics,

The Human Ecology Dialectic: Culture as a Behavioral Adaptation

Contrary to popular thought, which implicated the disengagement of Marx from anthropological theory, his dialectical concept will be applied to explain human ecology in a Boasian historical particularism milieu. Environmental conditions will be the common denominator for the Darwinian biogeography theory, intertwined with the cultural adaptation theory of Boas within the Human Ecology Dialectic (Taylor, 2014). Anthropologically, in a biological context the theories will explain the behavioral adaptation process demonstrated culturally by the prehistoric ancestors of the Inuit of the Canadian Central Arctic in their development and essential engagement in the creation of art; a pursuit that became a cultural tradition in historic and contemporary Inuit life. Art will be defined as objects of various forms and functions with aesthetic qualities made from raw organic resources such as bone, ivory, and stone

MCD and magnetization studies on nifB/nifZ minus molybdenum iron protein from Azotobacter vinelandii

This study reports a characterization of the iron-sulfur clusters of the MoFe protein expressed by the nifBnifZ deletion strain of A. vinelandii. VT-MCD spectroscopic and magnetization analysis of as-isolated ΔnifBΔnifZ MoFe protein were undertaken. VT-MCD spectra of as-isolated ΔnifBΔnifZ MoFe protein contains bands remarkably similar to those seen in as-isolated ΔnifH MoFe protein, assigned to arise from an [4Fe-4S]+ cluster. The low-temperature magnetization curve of as-isolated ΔnifBΔnifZ MoFe protein reveals the MCD spectra bands stem from an S = ½ spin system with diamagnetic contributions of some other species. As-isolated ΔnifBΔnifZ MoFe protein is compared with as-isolated ΔnifH MoFe protein, which contains a P-cluster precursor, and the as-isolated ΔnifB MoFe protein, which contains a fully assembled P-cluster ([8Fe-7S)]. Using nonlinear regression, the experimental magnetization curve of as-isolated ΔnifBΔnifZ MoFe protein is compared and factored to contributions from as-isolated ΔnifH MoFe protein and as-isolated ΔnifB MoFe protein. The simulation suggests a 1:1 ratio of ΔnifH MoFe protein to ΔnifB MoFe protein. These results suggests the as-isolated ΔnifBΔnifZ MoFe protein has an αβ subunit pair that contains a P-cluster and the other αβ subunit pair contains a latent (defined as immature, or potential) P-cluster (two [4Fe-4S] or P-cluster precursor)