Phase diagram of an exactly solvable t-J ladder model

We study a system of one-dimensional t-J models coupled to a ladder system. A special choice of the interaction between neighbouring rungs leads to an integrable model with supersymmetry, which is broken by the presence of rung interactions. We analyze the spectrum of low-lying excitations and ground state phase diagram at zero temperature.Comment: LaTeX, 8 pp. incl. 1 figur

Phase diagram of the su(8) quantum spin tube

We calculate the phase diagram of an integrable anisotropic 3-leg quantum spin tube connected to the su(8) algebra. We find several quantum phase transitions for antiferromagnetic rung couplings. Their locations are calculated exactly from the Bethe Ansatz solution and we discuss the nature of each of the different phases.Comment: 10 pages, RevTeX, 1 postscript figur

Third Neighbor Correlators of Spin-1/2 Heisenberg Antiferromagnet

We exactly evaluate the third neighbor correlator and all the possible non-zero correlators <S^{alpha}_j S^{beta}_{j+1} S^{gamma}_{j+2} S^{delta}_{j+3}> of the spin-1/2 Heisenberg $XXX$ antiferromagnet in the ground state without magnetic field. All the correlators are expressed in terms of certain combinations of logarithm ln2, the Riemann zeta function zeta(3), zeta(5) with rational coefficients. The results accurately coincide with the numerical ones obtained by the density-matrix renormalization group method and the numerical diagonalization.Comment: 4 page

Hypocrisy and culture: failing to practice what you preach receives harsher interpersonal reactions in independent (vs. interdependent) cultures

Failing to practice what you preach is often condemned as hypocrisy in the West. Three experiments and a field survey document less negative interpersonal reactions to misalignment between practicing and preaching in cultures encouraging individuals’ interdependence (Asian and Latin American) than in those encouraging independence (North American and Western Europe). In Studies 1–3, target people received greater moral condemnation for a misdeed when it contradicted the values they preached than when it did not – but this effect was smaller among participants from Indonesia, India, and Japan than among participants from the USA. In Study 4, employees from 46 nations rated their managers. Overall, the more that employees perceived a manager’s words and deeds as chronically misaligned, the less they trusted him or her – but the more employees’ national culture emphasized interdependence, the weaker this effect became. We posit that these cultural differences in reactions to failures to practice what one preaches arise because people are more likely to view the preaching as other-oriented and generous (vs. selfish and hypocritical) in cultural contexts that encourage interdependence. Study 2 provided meditational evidence of this possibility. We discuss implications for managing intercultural conflict, and for theories about consistency, hypocrisy, and moral judgment

Cytogenetic Studies of Normal and Cleft-Palate Epitheliums in Mice

This study investigated teratogenic activity on a cellular level through analysis of the cytogenetic complex in cleft-palate epithelial cells from the progenies of mice treated with cortisone. Analysis showed no detectable aberration from a normal chromosomal complement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68120/2/10.1177_00220345690480041601.pd

There and back again: migration in freshwater fishes

Animal migration is an amazing phenomenon that has fascinated humans for long. Many freshwater fishes also show remarkable migrations, whereof the spectacular mass migrations of salmonids from the spawning streams are the most well known and well studied. However, recent studies have shown that migration occurs in a range of freshwater fish taxa from many different habitats. In this review we focus on the causes and consequences of migration in freshwater fishes. We start with an introduction of concepts and categories of migration, and then address the evolutionary causes that drive individuals to make these migratory journeys. The basis for the decision of an individual fish to migrate or stay resident is an evaluation of the costs and benefits of different strategies to maximize its lifetime reproductive effort. We provide examples by discussing our own work on the causes behind seasonal migration in a cyprinid fish, roach (Rutilus rutilus (L., 1758)), within this framework. We then highlight different adaptations that allow fish to migrate over sometimes vast journeys across space, including capacity for orientation, osmoregulation, and efficient energy expenditure. Following this we consider the consequences of migration in freshwater fish from ecological, evolutionary, and conservation perspectives, and finally, we detail some of the recent developments in the methodologies used to collect data on fish migration and how these could be used in future research

Open su(4)-invariant spin ladder with boundary defects

The integrable su(4)-invariant spin-ladder model with boundary defect is studied using the Bethe ansatz method. The exact phase diagram for the ground state is given and the boundary quantum critical behavior is discussed. It consists of a gapped phase in which the rungs of the ladder form singlet states and a gapless Luttinger liquid phase. It is found that in the gapped phase the boundary bound state corresponds to an unscreened local moment, while in the Luttinger liquid phase the local moment is screened at low temperatures in analogy to the Kondo effect.Comment: Revtex 9 pages, published in PR