1,750 research outputs found
Critical points of the Black-Hole potential for homogeneous special geometries
We extend the analysis of N=2 extremal Black-Hole attractor equations to the
case of special geometries based on homogeneous coset spaces. For non-BPS
critical points (with non vanishing central charge) the (Bekenstein-Hawking)
entropy formula is the same as for symmetric spaces, namely four times the
square of the central charge evaluated at the critical point. For non
homogeneous geometries the deviation from this formula is given in terms of
geometrical data of special geometry in presence of a background symplectic
charge vector.Comment: 17 pages, LaTeX fil
Mathematical model of brain tumour with glia-neuron interactions and chemotherapy treatment
Acknowledgements This study was possible by partial financial support from the following Brazilian government agencies: Fundação Araucåria, EPSRC-EP/I032606/1 and CNPq, CAPES and Science Without Borders Program Process nos. 17656125, 99999.010583/2013-00 and 245377/2012-3.Peer reviewedPreprin
Seven new microendemic species of Brachycephalus (Anura:Brachycephalidae) from southern Brazil
Brachycephalus (Anura: Brachycephalidae) is a remarkable genus of miniaturized frogs of the Brazilian Atlantic Rainforest. Many of its species are highly endemic to cloud forests, being found only on one or a few mountaintops. Such level of microendemism might be caused by their climatic tolerance to a narrow set of environmental conditions found only in montane regions. This restriction severely limits the chance of discovery of new species, given the difficulty of exploring these inaccessible habitats. Following extensive fieldwork in montane areas of the southern portion of the Atlantic Rainforest, in this study we describe seven new species of Brachycephalus from the states of ParanĂĄ and Santa Catarina, southern Brazil. These species can be distinguished from one another based on coloration and the level of rugosity of the skin in different parts of their body. These discoveries increase considerably the number of described species of Brachycephalus in southern Brazil
Synchronization time in a hyperbolic dynamical system with long-range interactions
We show that the threshold of complete synchronization in a lattice of
coupled non-smooth chaotic maps is determined by linear stability along the
directions transversal to the synchronization subspace. We examine carefully
the sychronization time and show that a inadequate observation of the system
evolution leads to wrong results. We present both careful numerical experiments
and a rigorous mathematical explanation confirming this fact, allowing for a
generalization involving hyperbolic coupled map lattices.Comment: 22 pages (preprint format), 4 figures - accepted for publication in
Physica A (June 28, 2010
Geometric Transition as a Change of Polarization
Taking the results of hep-th/0702110 we study the Dijkgraaf-Vafa open/closed
topological string duality by considering the wavefunction behavior of the
partition function. We find that the geometric transition associated with the
duality can be seen as a change of polarization.Comment: 20 page
The CLIMALERT project: Climate alert smart system for sustainable water and agriculture
The vulnerability of sensitive European regions to hydro-meteorological extremes has
increased dramatically over the past few decades. Extreme weather and climate events are
increasingly happening worldwide due to ongoing climate change. As a consequence, hydro- meteorological disaster events are affecting the European economy, environment and
society, with impacts on food production, food distribution infrastructure, livelihood assets
and human health, in both rural and urban areas. Meanwhile, climate services have started
to be developed to further anticipate the impacts of climate variability and to apply climate
forecasts in different sectors, such as agriculture and water management. However, connections between climate information users and providers are still weak. The
CLIMALERT project emerges to provide climate information in a format that prospective
users find it easy to understand and/or incorporate into decision-making. The project main
goals are: i) strengthen the link between climate research, water resources and the
agriculture sector to assist the management of natural resources, enhance agricultural
livelihoods and reduce underlying causes of vulnerability, ii) improve the techniques and
tools currently used to incorporate weather and climate information into risk assessment and
decision making in agriculture and water sectors, and, iii) contribute to assist decision- makers in the implementation of adaptation and mitigation strategies. In this talk, we will
present the project framework, the study areas, the engagement with stakeholders, the
selection of climate and hydrological indicators, and the development of an alert system
platform that aims to contribute to reduce the risks and vulnerabilities for the agriculture and
water management sectors, providing economically valuable services and long-term benefits
to farmers and societyERA4CS/0004/2016 - CLIMALER
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