519 research outputs found
Empleo de aloinjerto óseo en la reparación quirúrgica de fracturas del platillo tibial
Cada vez es mayor el número de indicaciones posibles en el uso de aloinjertos en patología osteoarticular. Muchas veces supone una alternativa válida frente al uso de autoinjerto, evitando así la morbilidad que conlleva la extracción del injerto del propio paciente. Presentamos 6 casos de frac
tura de platillo tibial externo en las que existía depresión central y hundimiento de la superficie articular (tipo B3 según la clasificación AO) en cuyo tratamiento quirúrgico se ha utilizado el injerto óseo de banco (fragmento de cabeza femoral tallada a medida) para el soporte del platillo tibial deprimido una vez
levantado y conseguida la congruencia articular. En todos los casos se obtuvo un
resultado satisfactorio en cuanto a la función de soporte y a la consolidación sin existir complicaciones per o postoperatorias
Efficiency of evolutionary algorithms in water network pipe sizing
© 2015, Springer Science+Business Media Dordrecht. The pipe sizing of water networks via evolutionary algorithms is of great interest because it allows the selection of alternative economical solutions that meet a set of design requirements. However, available evolutionary methods are numerous, and methodologies to compare the performance of these methods beyond obtaining a minimal solution for a given problem are currently lacking. A methodology to compare algorithms based on an efficiency rate (E) is presented here and applied to the pipe-sizing problem of four medium-sized benchmark networks (Hanoi, New York Tunnel, GoYang and R-9 Joao Pessoa). E numerically determines the performance of a given algorithm while also considering the quality of the obtained solution and the required computational effort. From the wide range of available evolutionary algorithms, four algorithms were selected to implement the methodology: a PseudoGenetic Algorithm (PGA), Particle Swarm Optimization (PSO), a Harmony Search and a modified Shuffled Frog Leaping Algorithm (SFLA). After more than 500,000 simulations, a statistical analysis was performed based on the specific parameters each algorithm requires to operate, and finally, E was analyzed for each network and algorithm. The efficiency measure indicated that PGA is the most efficient algorithm for problems of greater complexity and that HS is the most efficient algorithm for less complex problems. However, the main contribution of this work is that the proposed efficiency ratio provides a neutral strategy to compare optimization algorithms and may be useful in the future to select the most appropriate algorithm for different types of optimization problems
Preparation of Palladium-Supported Periodic Mesoporous Organosilicas and their Use as Catalysts in the Suzuki Cross-Coupling Reaction
Three periodic mesoporous materials, i.e., two organosilicas with either ethylene
or phenylene bridges and one silica, have been used as supports for Pd nanoparticles. All
Pd-supported samples (1.0 wt%) were prepared by the incipient wetness method and
subsequently reduced in an H2 stream at 200 °C. Both hydrogen chemisorption and
temperature programmed reduction experiments revealed significant differences depending
on the support. Pd2+ species were more reducible on the mesoporous organosilicas than on
their silica counterpart. Also, remarkable differences on the particle morphology were
observed by transmission electron microscopy. All Pd-supported samples were active in
the Suzuki cross-coupling reaction between bromobenzene and phenylboronic aci
Monitoring Energy Efficiency in Buildings with Wireless Sensor Networks: NRG-WiSe Building
Teoría de la Señal y Comunicacione
Toxoplasma gondii infection and toxoplasmosis in farm animals: Risk factors and economic impact
The protozoan parasite Toxoplasma gondii is a zoonotic parasite that can be transmitted from animals to humans. Felids, including domestic cats, are definitive hosts that can shed oocysts with their feces. In addition to infections that occur by accidental oral uptake of food or water contaminated with oocysts, it is assumed that a large proportion of affected humans may have become infected by consuming meat or other animal products that contained infective parasitic stages of T. gondii. Since farm animals represent a direct source of infection for humans, but also a possible reservoir for the parasite, it is important to control T. gondii infections in livestock. Moreover, T. gondii may also be pathogenic to livestock where it could be responsible for considerable economic losses in some regions and particular farming systems, e.g. in areas where the small ruminant industry is relevant.
This review aims to summarize actual knowledge on the prevalence and effects of infections with T. gondii in the most important livestock species and on the effects of toxoplasmosis on livestock. It also provides an overview on potential risk factors favoring infections of livestock with T. gondii. Knowledge on potential risk factors is prerequisite to implement effective biosecurity measures on farms to prevent T. gondii infections. Risk factors identified by many studies are cat-related, but also those associated with a potential contamination of fodder or water, and with access to a potentially contaminated environment. Published information on the costs T. gondii infections cause in livestock production, is scarce. The most recent peer reviewed reports from Great Britain and Uruguay suggest annual cost of about 5–15 million US $ per country. Since these estimates are outdated, future studies are needed to estimate the present costs due to toxoplasmosis in livestock. Further, the fact that T. gondii infections in livestock may affect human health needs to be considered and the respective costs should also be estimated, but this is beyond the scope of this article
The Inverse Scattering Method, Lie-Backlund Transformations and Solitons for Low-energy Effective Field Equations of 5D String Theory
In the framework of the 5D low-energy effective field theory of the heterotic
string with no vector fields excited, we combine two non-linear methods in
order to construct a solitonic field configuration. We first apply the inverse
scattering method on a trivial vacuum solution and obtain an stationary
axisymmetric two-soliton configuration consisting of a massless gravitational
field coupled to a non-trivial chargeless dilaton and to an axion field endowed
with charge. The implementation of this method was done following a scheme
previously proposed by Yurova. We also show that within this scheme, is not
possible to get massive gravitational solitons at all. We then apply a
non-linear Lie-Backlund matrix transformation of Ehlers type on this massless
solution and get a massive rotating axisymmetric gravitational soliton coupled
to axion and dilaton fields endowed with charges. We study as well some
physical properties of the constructed massless and massive solitons and
discuss on the effect of the generalized solution generating technique on the
seed solution and its further generalizations.Comment: 17 pages in latex, changed title, improved text, added reference
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