Triangular flow in event-by-event ideal hydrodynamics in Au+Au collisions at √SNN = 200A GeV

The first calculation of triangular flow ν3 in Au+Au collisions at √sNN = 200A GeV from an event-by-event (3 + 1) d transport+hydrodynamics hybrid approach is presented. As a response to the initial triangularity Ie{cyrillic, ukrainian}3 of the collision zone, ν3 is computed in a similar way to the standard event-plane analysis for elliptic flow ν2. It is found that the triangular flow exhibits weak centrality dependence and is roughly equal to elliptic flow in most central collisions. We also explore the transverse momentum and rapidity dependence of ν2 and ν3 for charged particles as well as identified particles. We conclude that an event-by-event treatment of the ideal hydrodynamic evolution startingwith realistic initial conditions generates the main features expected for triangular flow. © 2010 The American Physical Society.

Institutional designs of customary fisheries management arrangements in Indonesia, Papua New Guinea, and Mexico

There are considerable efforts by governments, non-governmental organizations (NGOs), and academia to integrate marine conservation initiatives and customary practices, such as taboos that limit resource use. However, these efforts are often pursued without a fundamental understanding of customary institutions. This paper examines the operational rules in use and the presence of institutional design principles in long-enduring and dynamic customary fisheries management institutions in Papua New Guinea, Indonesia, and Mexico. Rather than a "blue print" for devising long-enduring institutions, this study relies on the design principles as a starting point to organize an inquiry into the institutional diversity found in customary governance regimes. Three important trends emerged from this comparative analysis: (1) despite it being notoriously difficult to define boundaries around marine resources, almost 3/4 of the cases in this study had clearly defined boundaries and membership; (2) all of the customary institutions were able to make and change rules, indicating a critical degree of flexibility and autonomy that may be necessary for adaptive management; (3) the customary institutions examined generally lacked key interactions with organizations operating at larger scales, suggesting that they may lack the institutional embeddedness required to confront some common pool resources (CPR) challenges from the broader socioeconomic, institutional and political settings in which they are embedded. Future research will be necessary to better understand how specific institutional designs are related to social and ecological outcomes in commons property institutions. © 2011 Elsevier Ltd.

Casual link and consensual arrangements in estoppel

Analyses the Court of Appeal decision in Powell v Benney on whether in a claim of proprietary estoppel the expectation of a couple that they would receive two properties owned, and promised to them, by a deceased friend was out of proportion to the detriment suffered by them in looking after the friend and improving his properties for their own use. Considers: (1) the approach to be taken to the requirement of a causal link between the assurance given and the conduct constituting the detriment relied on; and (2) consensual arrangements and estoppel equity.

Living arrangements, relationship to people in the household and admission to care homes for older people

Objective: to assess the separate contributions of marital status, living arrangements and the presence of children to subsequent admission to a care home.

Design and methods: a longitudinal study derived from the health card registration system and linked to the 2001 Census, comprising 28% of the Northern Ireland population was analysed using Cox regression to assess the likelihood of admission for 51,619 older people in the 6 years following the census. Cohort members’ age, sex, marital and health status and relationship to other household members were analysed.

Results: there were 2,138 care home admissions; a rate of 7.4 admissions per thousand person years. Those living alone had the highest likelihood of admission [hazard ratio (HR) compared with living with partner 1.66 (95% CI 1.48, 1.87)] but there was little difference between the never-married and the previously married. Living with children offered similar protection as living with a partner (HR 0.97; 95% CI 0.81, 1.16). The presence of children reduced admissions especially for married couples (HR 0.67 95% CI 0.54, 0.83; models adjusting for age, gender and health). Women were more likely to be admitted, though there were no gender differences for people living alone or those co-habiting with siblings.

Implications: presence of potential caregivers within the home, rather than those living elsewhere, is a major factor determining admission to care home. Further research should concentrate on the health and needs of these co-residents.

Entanglement properties of spin models in triangular lattices

The different quantum phases appearing in strongly correlated systems as well as their transitions are closely related to the entanglement shared between their constituents. In 1D systems, it is well established that the entanglement spectrum is linked to the symmetries that protect the different quantum phases. This relation extends even further at the phase transitions where a direct link associates the entanglement spectrum to the conformal field theory describing the former. For 2D systems much less is known. The lattice geometry becomes a crucial aspect to consider when studying entanglement and phase transitions. Here, we analyze the entanglement properties of triangular spin lattice models by also considering concepts borrowed from quantum information theory such as geometric entanglement.

Case study of the uniaxial anisotropic spin-1 bilinear-biquadratic Heisenberg model on a triangular lattice

We study the spin-1 model on a triangular lattice in the presence of a uniaxial anisotropy field using a cluster mean-field (CMF) approach. The interplay among antiferromagnetic exchange, lattice geometry, and anisotropy forces Gutzwiller mean-field approaches to fail in a certain region of the phase diagram. There, the CMF method yields two supersolid phases compatible with those present in the spin-1/2 XXZ model onto which the spin-1 system maps. Between these two supersolid phases, the three-sublattice order is broken and the results of the CMF approach depend heavily on the geometry and size of the cluster. We discuss the possible presence of a spin liquid in this region.