188 research outputs found
Stability of benthic coral reef communities: top-down herbivory control versus bottom-up eutrophication
Potential effect of mangrove regression for fish species of commercial interest in Guadeloupe
La Partición de los Recursos Tróficos Permite la Formación de Grupos Multi-Específicos de Acanthuridae (Guadeloupe, Antillas Menores)
A first record of a Sargassum (Phaeophyta, Algae) outbreak in a Caribbean coral reef ecosystem
Asymptotic symmetries in 3d gravity with torsion
We study the nature of asymptotic symmetries in topological 3d gravity with
torsion. After introducing the concept of asymptotically anti-de Sitter
configuration, we find that the canonical realization of the asymptotic
symmetry is characterized by the Virasoro algebra with classical central
charge, the value of which is the same as in general relativity: c=3l/2G.Comment: 25 pages, RevTeX, no figure
Asymptotic dynamics in 3D gravity with torsion
We study the nature of boundary dynamics in the teleparallel 3D gravity. The
asymptotic field equations with anti-de Sitter boundary conditions yield only
two non-trivial boundary modes, related to a conformal field theory with
classical central charge. After showing that the teleparallel gravity can be
formulated as a Chern-Simons theory, we identify dynamical structure at the
boundary as the Liouville theory.Comment: 16 pages, RevTeX, no figure
Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption
ETH authors thanks for the grant ETH 33 15-1. PE and JČ acknowledge the financial support from the Czech Science Foundation (P106/12/0189). JPR and JČ gratefully acknowledge the financial support from the European Union Seventh Framework Programme (FP7/ 2007-2013) under grant agreement no. 604307. HRTEM characterization was performed at the Advanced Microscopy Laboratory (LMA) and the research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3).The advanced investigation of pore networks in isoreticular zeolites and mesoporous materials related to the IPC family was performed using high-resolution argon adsorption experiments coupled with the development of a state-of-the-art non-local density functional theory approach. The optimization of a kernel for model sorption isotherms for materials possessing the same layer structure, differing only in the interlayer connectivity (e.g. oxygen bridges, single- or double-four-ring building units, mesoscale pillars etc.) revealed remarkable differences in their porous systems. Using high-resolution adsorption data, the bimodal pore size distribution consistent with crystallographic data for IPC-6, IPC-7 and UTL samples is shown for the first time. A dynamic assessment by positron annihilation lifetime spectroscopy (PALS) provided complementary insights, simply distinguishing the enhanced accessibility of the pore network in samples incorporating mesoscale pillars and revealing the presence of a certain fraction of micropores undetected by gas sorption. Nonetheless, subtle differences in the pore size could not be discriminated based on the widely-applied Tao-Eldrup model. The combination of both methods can be useful for the advanced characterization of microporous, mesoporous and hierarchical materials.PostprintPeer reviewe
Molar mass estimate of dark matter from the dark mass distribution measurements
We study the distribution of dark matter versus visible matter using a set of
data obtained from strong gravitational lensing in the galaxy cluster
CL0024+1654 and another set of data inferred from the universal rotation curves
in spiral galaxies. The important feature of these two dramatically different
observations is that the mass density profile of both visible and dark
components can be estimated. From these measurements we deduce the mass of the
dark matter particle and our estimate of the mass for the dark matter particle
is MeV. We contrast our estimates from CL0024+1654
data and the universal rotation curves of the spiral galaxies and discuss their
consistency.Comment: 14 pages, 13 figure
Regulating mobility in the Peruvian Andes: road safety, social hierarchies and governmentality in Cusco's rural provinces
Significant developments in road safety regulation have taken place in Peru during recent years, reflecting international efforts to reduce worldwide fatalities and injuries. A series of measures has sought to bring about transformations in governmentality among passengers on public transport. Seen ethnographically, these have had uneven success on the ground. In rural provinces of Cusco, situated histories and sociologies of mobility have sometimes led to ambivalence, unobtrusive resistance or reinforcement of discriminatory attitudes. This article explores how reception of the regulations has been refracted through class, ethnic and geographical divisions within Peruvian society, and argues for both the applied and theoretical utility of anthropological study of road safety governance
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