Catastrophe for Central America? Jorge A. Huete-Perez,†,∥,* Jose G. Tundisi,‡ and Pedro J. J. Alvarez†,§ †Academy of Sciences of Nicaragua and University of Central America, UCA, Rotonda R. Dario 150 mts Oeste, Apartado 69, Managua, Nicaragua ‡International Institute of Ecology. Saõ Carlos, Brazil. Rua Bento Carlos 750, Saõ Carlos, Saõ Paulo, 13560-660 Brazil Department of Civil & Environmental...

In an earlier paper (Nunez & Colhoun 1986), the gradient of near-surface air temperature with altitude, commonly known as the environmental lapse rate (ELR), was obtained for Mount Wellington, Tasmania. Comparing these local lapse rates with an ELR for the entire island did not give good agreement for maximum temperatures in summer or minimum temperatures in winter. These differences are attrib...

A picture of a bush dog Speothos venaticus was obtained with a minimum sampling effort of 4,818 camera days, using seven to ten era traps during 922 days at Parque Estadual Carlos Botelho, an Atlantic forest site. This picture confirms the presence of the species the state of São Paulo, Brazil.

The eligibility trace is one of the most used mechanisms to speed up reinforcement learning. Earlier reported experiments seem to indicate that replacing eligibility traces would perform better than accumulating eligibility traces. However, replacing traces are currently not applicable when using function approximation methods where states are not represented uniquely by binary values. This pap...

In this article we consider the differential inclusion − div(|∇u|p(x)−2∇u) ∈ ∂F (x, u) in Ω, u = 0 on ∂Ω which involves the p(x)-Laplacian. By applying the nonsmooth Mountain Pass Theorem, we obtain at least one nontrivial solution; and by applying the symmetric Mountain Pass Theorem, we obtain k-pairs of nontrivial solutions in W 1,p(x) 0 (Ω).

Departamento de Quı́mica e Bioquı́mica, Faculdade de Ciências da UniVersidade de Lisboa, 1749-016 Lisboa, Portugal, Grupo de Fı́sica Matemática da UniVersidade de Lisboa, AV. Professor Gama Pinto 2, 1649-003 Lisboa, Portugal, UniVersidade de Mogi das Cruzes, CP 411, 08701-970 Mogi das Cruzes, São Paulo, Brazil, Instituto de Fı́sica, UniVersidade de São Paulo, CP 66318, 05315-970 São Paulo, São Paul...

The nature of the obscuring material in active galactic nuclei is still uncertain. Although some sources, such as Cygnus A, show evidence for a geometrically thick “torus” as originally suggested, recent work on the radiation-driven warping instability discovered by Pringle suggests that obscuration by thin, warped disks may play a crucial role in AGN.

By using the Mountain Pass Theorem, we establish some existence criteria to guarantee the second-order nonlinear difference equation ∆ [p(t)∆u(t − 1)] + f(t, u(t)) = 0 has at least one homoclinic orbit, where t ∈ Z, u ∈ R.

Paulo Sampaio, Pedro Saraiva, António Guimarães Rodrigues 1*. Researcher, PhD, University of Minho, Production and Systems Department, Campus de Gualtar, 4710-057 Braga, Portugal, Phone: +351 253 604 756, [email protected] 2. Associate Professor, University of Coimbra, Chemical Engineering Department, Pólo II Pinhal de Marrocos, 3030-290 Coimbra, Portugal. 3. Full Professor, University...