646 research outputs found
SALUD Y RESERVA EN EL EJÉRCITO DE TIERRA
In today's society increased life expectancy has led to an increase in the number of people in early retirement. This phenomenon is not unique to the civilian population but is also found in the military population known as “Reserva”. In the Army, depending on the position held, each soldier sooner or later reaches retirement. The goal of this study is to determine how the health of army people who in 1 or 2 years will retire is affected. To evaluate the health variable in this population, we used the Goldberg Health Questionnaire GHQ-28. The results showed that over 80% of the subjects interviewed are either “well” or “very well”.El aumento de las expectativas de vida en la sociedad actual determina que cada vez sea mayor el número de personas en la fase de prejubilación. Este fenómeno no es exclusivo de la población civil sino que también se da en la población militar, llamado en ella “Reserva”. En el Ejército de Tierra, dependiendo del status militar que se desempeñe, pasas antes o después a la Reserva. El objetivo del presente estudio ha sido conocer de qué manera se ve afectada la salud en las personas del Ejército de Tierra que están a 1 ó 2 años de pasar a la Reserva. Para la evaluación de la variable salud se ha utilizado el cuestionario de salud de Goldberg GHQ-28. Los resultados indican que más del 80% de la población estudiada está “bien” o “muy bien” según dicho cuestionario
Vacuum solutions of the gravitational field equations in the brane world model
We consider some classes of solutions of the static, spherically symmetric
gravitational field equations in the vacuum in the brane world scenario, in
which our Universe is a three-brane embedded in a higher dimensional
space-time. The vacuum field equations on the brane are reduced to a system of
two ordinary differential equations, which describe all the geometric
properties of the vacuum as functions of the dark pressure and dark radiation
terms (the projections of the Weyl curvature of the bulk, generating non-local
brane stresses). Several classes of exact solutions of the vacuum gravitational
field equations on the brane are derived. In the particular case of a vanishing
dark pressure the integration of the field equations can be reduced to the
integration of an Abel type equation. A perturbative procedure, based on the
iterative solution of an integral equation, is also developed for this case.
Brane vacuums with particular symmetries are investigated by using Lie group
techniques. In the case of a static vacuum brane admitting a one-parameter
group of conformal motions the exact solution of the field equations can be
found, with the functional form of the dark radiation and pressure terms
uniquely fixed by the symmetry. The requirement of the invariance of the field
equations with respect to the quasi-homologous group of transformations also
imposes a unique, linear proportionality relation between the dark energy and
dark pressure. A homology theorem for the static, spherically symmetric
gravitational field equations in the vacuum on the brane is also proven.Comment: 13 pages, no figures, to appear in PR
The abundance, diversity, and metabolic footprint of soil nematodes is highest in high elevation alpine grasslands
info:eu-repo/semantics/publishedVersio
Pretratamiento con hialuronidasa mejora la tinción de colágeno en notocorda de esturión
Objective: The current study aimed to design a histological method to determine the presence and organization
of the collagen network in sturgeon notochord.
Methods: Serial sections of sturgeon notochord (Acipenser naccarii) were used and assigned to two different
experimental groups: Hyaluronidase pre-treatment (HP) in an alcohol acid solution (1% HCl in 70% alcohol
solution) for 15 min and hyaluronidase solution in a 2 µg/ ml concentration (pre-heated at 37º C), and
control (CTR) group, without pre-treatment. Then, the ECM was assessed by two histochemical methods:
Picrosirius Red (PR) staining for 30 min with Sirius red (0.1% of Sirius red in saturated aqueous picric acid),
for collagen bundle staining, and Alcian Blue (AB) staining for glycosaminoglycans detection.
Results: Samples analyzed in this study showed positive histochemical reaction for collagen fibers in both
experimental groups. Referring to PR staining, the CTR group presented a larger and homogeneous reaction
was observed in the entire samples, whereas HP group presented a more definite and intense pattern of
collagen network. Also, this more intense signal in HP group matched with an increase of birefringence in
polarized microscopy images of PR. However, HP group showed a lower intense and more heterogeneous
signal when was compared with CTR group in AB staining.
Conclusion: Using a simple histological example, our study illustrates the capability of a hyaluronidase pre-treatment
to enhance picrosirius red staining in sturgeon notochord trough light and polarized microscopy.Objetivo: El presente estudio tiene por objetivo diseñar un método histológico para determinar la presencia
y organización de la red de colágeno en la notocorda del esturión.
Métodos: Secciones seriada de la notocorda de esturión (Acipenser naccarii) fueron utilizadas y se asignaron
a dos grupos experimentales diferentes: pretratamiento de hialuronidasa (HP) en una solución de alcohol
ácido (HCl al 1% en solución de alcohol al 70%) durante 15 minutos y posteriormente a una solución
de hialuronidasa en una concentración de 2 μg / ml (precalentada a 37º C) y grupo de control (CTR), sin
tratamiento previo. Luego, la ECM se evaluó mediante dos métodos histoquímicos: tinción Picrosirius Red
(PR) durante 30 minutos con rojo Sirio (0,1% de rojo Sirio en una solución saturada de ácido pícrico), para
la tinción de colágeno; y tinción con Alcian Blue (AB) para detección de glicosaminoglicanos.
Resultados: Las muestras analizadas en este estudio mostraron una reacción histoquímica positiva para
las fibras de colágeno en ambos grupos experimentales. Con respecto a la tinción PR, el grupo CTR presentó
una reacción mayor y más homogénea en toda la superficie de las muestras, mientras que el grupo
HP presentó un patrón red de colágeno más definido e intenso. Además, esta señal más intensa en el
grupo HP coincidió con un aumento de la birrefringencia en las imágenes de microscopía polarizada de
PR. Sin embargo, el grupo HP mostró una señal menos intensa y más heterogénea cuando se comparó con
el grupo CTR en la tinción AB.
Conclusión: Utilizando un ejemplo histológico simple, nuestro estudio ilustra la capacidad de un pretratamiento
de hialuronidasa para mejorar la tinción de picrosirius en la notocorda del esturión a través de la
luz y la microscopía polarizada
Active Front-End converter applied for the THD reduction in power systems
The Active Front-End (AFE) converter topology is generated by modifying a conventional back-to-back converter, from using a single VSC to use pVCS connected in parallel. The AFE configuration improves the capability, efficiency and reliability of energy conversion devices connected to the power system. In this paper, a novel technique to reduce the total harmonic distortion (THD) in an AFE converter topology is proposed and analyzed. The THD reduction is achieved by applying a phase shift angle in the SPWM switching signals of each AFE converter VSC. To verify the functionality and robustness of the proposed methodology, the power system simulation in Matlab-Simulink is analyzed for a type-4 wind turbine converter with total power output of 9MW. The obtained simulation results show a THD reduction up to 2.5 for AFE connected to the power network
Root-colonizing bacteria enhance the levels of (E)-β-caryophyllene produced by maize roots in response to rootworm feeding.
When larvae of rootworms feed on maize roots they induce the emission of the sesquiterpene (E)-β-caryophyllene (EβC). EβC is attractive to entomopathogenic nematodes, which parasitize and rapidly kill the larvae, thereby protecting the roots from further damage. Certain root-colonizing bacteria of the genus Pseudomonas also benefit plants by promoting growth, suppressing pathogens or inducing systemic resistance (ISR), and some strains also have insecticidal activity. It remains unknown how these bacteria influence the emissions of root volatiles. In this study, we evaluated how colonization by the growth-promoting and insecticidal bacteria Pseudomonas protegens CHA0 and Pseudomonas chlororaphis PCL1391 affects the production of EβC upon feeding by larvae of the banded cucumber beetle, Diabrotica balteata Le Conte (Coleoptera: Chrysomelidae). Using chemical analysis and gene expression measurements, we found that EβC production and the expression of the EβC synthase gene (tps23) were enhanced in Pseudomonas protegens CHA0-colonized roots after 72 h of D. balteata feeding. Undamaged roots colonized by Pseudomonas spp. showed no measurable increase in EβC production, but a slight increase in tps23 expression. Pseudomonas colonization did not affect root biomass, but larvae that fed on roots colonized by P. protegens CHA0 tended to gain more weight than larvae that fed on roots colonized by P. chlororaphis PCL1391. Larvae mortality on Pseudomonas spp. colonized roots was slightly, but not significantly higher than on non-colonized control roots. The observed enhanced production of EβC upon Pseudomonas protegens CHA0 colonization may enhance the roots' attractiveness to entomopathogenic nematodes, but this remains to be tested
de Sitter Thick Brane Solution in Weyl Geometry
In this paper, we consider a de Sitter thick brane model in a pure geometric
Weyl integrable five-dimensional space-time, which is a generalization of
Riemann geometry and is invariant under a so-called Weyl rescaling. We find a
solution of this model via performing a conformal transformation to map the
Weylian structure into a familiar Riemannian one with a conformal metric. The
metric perturbations of the model are discussed. For gravitational
perturbation, we get the effective modified Pschl-Teller
potential in corresponding Schrdinger equation for
Kaluza-Klein (KK) modes of the graviton. There is only one bound state, which
is a normalizable massless zero mode and represents a stable 4-dimensional
graviton. Furthermore, there exists a mass gap between the massless mode and
continuous KK modes. We also find that the model is stable under the scalar
perturbation in the metric. The correction to the Newtonian potential on the
brane is proportional to , where is the de Sitter
parameter of the brane. This is very different from the correction caused by a
volcano-like effective potential.Comment: 24 pages, 13 figures, published versio
Subterranean, herbivore-induced plant volatile increases biological control activity of multiple beneficial nematode species in distinct habitats
While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9-12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.info:eu-repo/semantics/publishedVersio
European grapevine moth, Lobesia botrana Part I: biology and ecology
Though the European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) can feed on more than forty plant species, grapevine is the preferred crop worldwide. This moth is a western palearctic species that has recently spread to Chile, Argentina, and California. The possible further expansion in other regions of the Americas is greatly feared and should be monitored carefully in the near future. In this framework, we provide an updated review of the current knowledge on its taxonomy, morphology, biology, ecology, genomics, geographic distribution, and invasiveness. Then, in the last section, we develop a research agenda pointing out significant challenges for future investigations on bio-ecology and invasion biology, which are tightly connected with the prevention and management strategie
European grapevine moth, Lobesia botrana Part II: prevention and management
Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), commonly known as the European grapevine moth (EGVM), is a primary pest of vineyards. This article provides an updated review of its monitoring, modelling, and management tools. EGVM management strategies analysed here include insecticide-based control, insecticide resistance, side-effects (particularly those caused by the exposure to sublethal doses of pesticides), cultural control, sterile insect technique, pheromone-mediated control strategies (with special reference to pheromone-based mating disruption), biological control, and area-wide control programs. Lastly, we outline significant challenges for future EGVM research and sustainable control implementatio
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