1,307 research outputs found
Caracterización preliminar de las interacciones aguas subterráneas-humedales-ser humano en Iberoamérica y en la Península Ibérica
El proyecto UNESCO IGCP 604 tiene como objetivo elaborar un marco conceptual sobre las interacciones aguas subterráneas–humedales-ser humano, y está motivado por el Programa de Evaluación de los Ecosistemas del Milenio de Naciones Unidas. Como resultados preliminares se ha elaborado información de catorce humedales en nueve países. Sus características morfológicas, hidrológicas, químicas, etc. son muy variables. Solamente los servicios de abastecimiento de agua y de regulación hídrica parecen estar ampliamente extendidos, con una tendencia dominante a mantenerse estables o a empeorar. Todos los servicios culturales son frecuentes y muestran una tendencia mayoritaria a mejorar. Entre los factores que inducen cambios en los servicios, los de impacto más extendido son: extracción de agua, cambios en el uso de suelo, contaminación y cambio climático y global. Presentan impactos variables, pero la tendencia general es a mantenerse estables o a aumentar.This paper presents the preliminary results of The UNESCO project IGCP 604, whose objec-tive is to elaborate a conceptual framework on groundwater-wetland-human beings interactions, and is moti-vated by the UNESCO Millennium Ecosystems Assessment Programme. Data from fourteen wetlands in nine countries have been elaborated. Their morphological, hydrological, chemical, etc. characteristics are highly variable. Only the water supply and water regulation services seem to be widely extended, and their general evolution trend is to be stable or to worsen. All the cultural services seem to be widely extended, and the dominant trend is to improve. The factors that most widely induce changes in wetland services are water ex-traction, biological exploitation, changes in land use, pollution, and climate and global change. They cause variable impacts, which tend to be stable or to increase
Cáncer, quimioterapia y un corazón roto. Reporte de un caso de cardiomiopatía de Takotsubo asociada a quimioterapia
Introducción: El nexo entre quimioterapia y Cardiomiopatía de Takotsubo es cada vez más reconocido en años recientes, pero aunque la causalidad está establecida, los reportes aún son escasos, la cantidad de fármacos relacionados es creciente y los mecanismos de acción no están completamente dilucidados. Reporte de caso: Se presenta el caso de una paciente con Mieloma Múltiple que luego de una sesión de quimioterapia con Ciclofosfamida y Talidomida, desarrolla de forma súbita un cuadro compatible con síndrome coronario agudo; fue sometida a una angiocoronariografía que mostró arterias coronarias sin lesiones significativas, y balonamiento apical, hallazgos consistentes con Cardiomiopatía de Takotsubo. Conclusiones: La Miocardiopatía de Takotsubo puede representar una forma de disfunción cardiaca dentro del espectro de la cardiotoxicidad inducida por quimioterapia, que difiere de la forma más común que es la toxicidad por dosis acumulada. Dada la cantidad creciente de casos reportados, incluso la presencia de recidiva tras la re administración del mismo agente quimioterápico, deben identificarse adecuadamente los implicados y evitar su uso en pacientes de alto riesgo
Isotopic and hydrogeochemical characterization of high-altitude karst aquifers in complex geological settings. The Ordesa and Monte Perdido National Park (Northern Spain) case study.
The Ordesa and Monte Perdido National Park, located in the Southern Pyrenees, constitutes the highest karst system in Western Europe. No previous studies regarding its geochemical and isotopic groundwater characterization are available in this area. This work presents the results of field and sampling campaigns carried out between July 2007 and September 2013. The groundwater presents high calcium bicarbonate contents due to the occurrence of upper Cretaceous and lower Paleocene-Eocene carbonate materials in the studied area. Other relevant processes include dissolution of anhydrite and/or gypsum and incongruent dissolution of Mg-limestone and dolomite. The water stable isotopes (δ18O, δ2H) showthat the oceanic fronts from the Atlantic Ocean are responsible for the high levels of precipitation. In autumn, winter, and spring, a deuterium excess is found in the rechargewater,which could be related to local atmospheric transport of low-altitude snow sublimation vapour and its later condensation on the snowsurface at higher altitude,where recharge ismostly produced. The recharge zones are mainly between 2500mand 3200ma.s.l. The tritiumcontent of the water suggests short groundwater transit times. The isotopic composition of dissolved sulphate points to the existence of regional fluxes mixed with local discharge in some of the springs. This work highlights the major role played by the altitude difference between the recharge and discharge zones in controlling the chemistry and the vertical variability of the isotopic composition in high-altitude karst aquifers
On the construction of model Hamiltonians for adiabatic quantum computation and its application to finding low energy conformations of lattice protein models
In this report, we explore the use of a quantum optimization algorithm for
obtaining low energy conformations of protein models. We discuss mappings
between protein models and optimization variables, which are in turn mapped to
a system of coupled quantum bits. General strategies are given for constructing
Hamiltonians to be used to solve optimization problems of
physical/chemical/biological interest via quantum computation by adiabatic
evolution. As an example, we implement the Hamiltonian corresponding to the
Hydrophobic-Polar (HP) model for protein folding. Furthermore, we present an
approach to reduce the resulting Hamiltonian to two-body terms gearing towards
an experimental realization.Comment: 35 pages, 8 figure
Black hole thermodynamics with generalized uncertainty principle
In the standard viewpoint, the temperature of a stationary black hole is
proportional to its surface gravity, . This is a
semiclassical result and the quantum gravity effects are not taken into
consideration. This Letter explores a unified expression for the black hole
temperature in the sense of a generalized uncertainty principle(GUP). Our
discussion involves a heuristic analysis of a particle which is absorbed by the
black hole. Besides a class of static and spherically symmetric black holes, an
axially symmetric Kerr-Newman black hole is considered. Different from the
existing literature, we suggest that the black hole's irreducible mass
represent the characteristic size in the absorption process. The information
capacity of a remnant is also discussed by Bousso's D-bound in de Sitter
spacetime.Comment: 18 pages, great improvement on the first version; a Kerr-Newman black
hole is considere
Informações geoespaciais para a gestão dos recursos naturais do "Corredor de Maputo" - Moçambique.
The Technical Cooperation Project for Mozambique's Agricultural Innovation Platform (EmbrapaMozambique Project) was based on the edaphoclimatic similarities between Mozambique's savannas and the Brazilian Cerrado. This component of the EmbrapaMozambique Project aims at organizing the geospatial data obtained for the management of the natural resources and for the agricultural development of the "Maputo Corridor". The geographical information plans were obtained from different Mozambican and international organizations/institutions, and were separated into geospatial information groups: political-administrative limits, transport network, hydrographic network, soil use, soils, drainage, agroecological zones, agricultural aptitude, climate, hydrography and ecological zones. The process of generating and making the database available in the form of analogical maps supported the process of updating the Project's geospatial data obtained on the mission made to Mozambique in May 2012.Pages: 5971-597
On Fields with Finite Information Density
The existence of a natural ultraviolet cutoff at the Planck scale is widely
expected. In a previous Letter, it has been proposed to model this cutoff as an
information density bound by utilizing suitably generalized methods from the
mathematical theory of communication. Here, we prove the mathematical
conjectures that were made in this Letter.Comment: 31 pages, to appear in Phys.Rev.
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