12,483 research outputs found

    Rotational symmetry and degeneracy: a cotangent-perturbed rigid rotator of unperturbed level multiplicity

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    We predict level degeneracy of the rotational type in diatomic molecules described by means of a cotangent-hindered rigid rotator. The problem is shown to be exactly solvable in terms of non-classical Romanovski polynomials. The energies of such a system are linear combinations of t(t+1) and 1/[t(t+1)+1/4] terms with the non-negative integer principal quantum number t=n+|/bar{m}| being the sum of the degree n of the polynomials and the absolute value, |/bar{m}|, of the square root of the separation constant between the polar and azimuthal motions. The latter obeys, with respect to t, the same branching rule, |/bar{m}|=0,1,..., t, as does the magnetic quantum number with respect to the angular momentum, l, and, in this fashion, the t quantum number presents itself indistinguishable from l. In effect, the spectrum of the hindered rotator has the same (2t+1)-fold level multiplicity as the unperturbed one. For small t values, the wave functions and excitation energies of the perturbed rotator differ from the ordinary spherical harmonics, and the l(l+1) law, respectively, while approaching them asymptotically with increasing t. In this fashion the breaking of the rotational symmetry at the level of the representation functions is opaqued by the level degeneracy. The model provides a tool for the description of rotational bands with anomalously large gaps between the ground state and its first excitation.Comment: 10 pages, 6 figures; Molecular Physics 201

    The influence of topic and systemic administration of copaiba oil on the alveolar wound healing after tooth extraction in rats

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    The Copaiba oil has been used as an auxiliary treatment of inflammations, skin disorders and stomach ulcers, however, in dentistry, this alternative medicine has not been investigated yet. The purpose of this study was to evaluate the influence of topic and systemic administration of copaiba oil on the alveolar wound healing after tooth extraction. Twenty-eight wistar male rats had their lower first molar teeth extracted. Subsequently, they were divided in four groups, according to the treatment performed: (a) alveolar socket irrigation with copaiba oil; (b) alveolar socket irrigation with physiological serum; (c) daily gavage with copaiba oil or (d) daily gavage with physiological serum. After the sacrifice, the mandibles were removed and processed in order to obtain decalcified histological sections. The results demonstrated high level of epithelial migration, small number of inflammatory cells and vascular enhancement in the animals which received systemic administration of copaiba oil. The rats treated with topic administration of copaiba oil presented ulcerations and large number of inflammatory cells. An increased bone neoformation was observed in both groups treated with copaiba oil when compared with placebo group. It could be concluded that topic or systemic administration of copaiba oil leads to a better alveolar bone healing, however the topic application on connective tissue should be carefully considered, regarding the whole socket wound healing

    La comunicación institucional y de servicios. Las páginas web municipales de las capitales de provincia españolas

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    Computing has taken the chief role in the society during recent years and has compelled the different institutions that shape our society to adapt to the new situation. In the area of public Administration is notable the modernization and adaptation process started by the local institutions which are closer to the citizens: the city councils. In this period full of changes, the new information and communication technologies take the main role and lead us to a new local Administration where limits of time and space disappear. There is a change in the way services are offered and in the relationship between citizens and their city councils. In this investigation the authors have studied if the municipal webs are operative and functional allowing people to transact and to manage official documents without presenting oneself at city council.El papel protagonista que ha adquirido la informática en estos últimos años obliga a los diferentes agentes e instituciones que conforman nuestra sociedad a adecuarse a los nuevos tiempos. Entre las Administraciones públicas destaca el proceso de modernización y adaptación iniciado por las instituciones locales más próximas a los ciudadanos: los ayuntamientos. En este periodo de transformación, las nuevas tecnologías de la información y las comunicaciones ocupan un papel principal y nos conducen a una nueva Administración local donde desaparecen las limitaciones de tiempo y espacio. Se produce una revolución en la prestación de servicios y un cambio en las relaciones que mantienen los ciudadanos con los ayuntamientos. En esta investigación se va a estudiar si las webs municipales españolas son operativas y funcionales, permitiendo la gestión de trámites burocráticos a través de la red y, por tanto, sin la necesidad de personarse en el consistorio

    Stability conditions for fermionic Ising spin-glass models in the presence of a transverse field

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    The stability of spin-glass (SG) phase is analyzed in detail for a fermionic Ising SG (FISG) model in the presence of a magnetic transverse field Γ\Gamma. The fermionic path integral formalism, replica method and static approach have been used to obtain the thermodynamic potential within one step replica symmetry breaking ansatz. The replica symmetry (RS) results show that the SG phase is always unstable against the replicon. Moreover, the two other eigenvalues λ±\lambda_{\pm} of the Hessian matrix (related to the diagonal elements of the replica matrix) can indicate an additional instability to the SG phase, which enhances when Γ\Gamma is increased. Therefore, this result suggests that the study of the replicon can not be enough to guarantee the RS stability in the present quantum FISG model, especially near the quantum critical point. In particular, the FISG model allows changing the occupation number of sites, so one can get a first order transition when the chemical potential exceeds a certain value. In this region, the replicon and the λ±\lambda_{\pm} indicate instability problems for the SG solution close to all range of first order boundary.Comment: 15 pages, 4 figures, accepted in Physica

    Physical capacity in youth football players of a profesional club

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    Las características físicas del fútbol son muy diversas, aunque se reconocen como muy importantes la capacidad de realizar esfuerzos de alta intensidad y la de retrasar la fatiga en la mayor medida posible en esfuerzos intermitentes. Son diversos los trabajos que analizan dichas características en el fútbol profesional, aunque son menores los que analizan las categorías de formación. En el presente estudio se analiza la evolución por categorías de pruebas de salto, velocidad, agilidad y resistencia aeróbica específica, en jugadores de fútbol jóvenes de la cantera de un club profesional de la liga española. Se produjo un incremento de las marcas con la edad, aunque no se observaron diferencias significativas en grupos de edad cercanos, produciéndose una meseta en el rendimiento en la fuerza explosiva y velocidad de aceleración a partir de los 17 años y en la velocidad de desplazamiento y agilidad a los 15 añosPhysical characteristics of football are very different, but are recognized as very important the ability to perform high-intensity efforts and to delay fatigue as much as possible in intermittent efforts. There are several studies that analyze these characteristics in professional football but are less those who analyze the categories of training. In the present study analyzes the evolution of categories of jumping, speed, agility and specific endurance in young soccer players from a professional club of the Spanish league. There was an increase of the marks with age, although no significant differences in age groups encircle. Producing a plateau in performance in explosive strength and acceleration speed from 17 years and in speed and agility at age of 1

    Alteraciones en la tasa de respiración de Daphnia magna bajo concentraciones subletales de anatoxina-a

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    Anatoxina-a es una potente neurotoxina producida por cianobacterias dulceacuícolas que puede representar un riesgo, por sus efectos agudos, para diferentes formas de vida, incluyendo los seres humanos. Aunque se conocen los efectos agudos y crónicos de esta toxina, pocos estudios aportan datos de medidas de efectos subletales sobre la respiración del zooplancton. En este trabajo se cuantifican cambios en la respiración de Daphnia magna bajo una concentración subletal de anatoxina-a, en condiciones experimentales, por medio de un sistema automatizado de medida en continuo de consumo de Oxígeno. Los resultados indican que la presencia de anatoxina-a en dosis subletales reduce significativamente la actividad respiratoria en esta especie, con efectos, dependientes de la edad del organismo.Anatoxin-a is a potent neurotoxin produced by some freshwater cyanobacteria which, because of its acute toxic effects, may represent a hazard to aquatic organisms, and even to human beings. Both the acute and chronic effects of this toxin are rather well known, but few studies provided information about its sublethal effect on the zooplankton respiration. In this paper we have quantified respiration changes in Daphnia magna under sublethal anatoxin-a concentrations in experimental conditions, using an automatic open-flow system of continuous measurement of oxygen consumption. Our results show that the presence of anatoxin-a at sublethal doses reduces significantly the respiratory activity of the animals, being the effects greatly dependent on the individual age

    Effect of the phosphate fertilizer with filter cake on soil microbial activity and phosphorous uptake in sugar cane

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    El objetivo del trabajo fue evaluar el efecto de diferentes dosis de fertilizante fosfatado con la adición de cachaza sobre la actividad microbiana del suelo, y el contenido de fósforo en el suelo y en plantas de caña de azúcar. El experimento se condujo en condi- ciones de invernadero en Jaboticabal Brasil en 2013, usándose plántulas de caña de azúcar (variedad "CTC 05"). Las unidades experimentales estuvieron constituidas por macetas cargadas con un Hapludox. Se empleó un diseño completamente aleatorizado, con el arreglo factorial de 5x2 y tres repeticiones. Los tratamientos fueron cinco dosis de fósforo: 0, 50, 100, 200 y 400 mg dm -3 y dos niveles de cachaza (ausencia y presencia). Se evaluaron la actividad respiratoria, la fosfatasa ácida y la deshidrogenasa, el carbono soluble, el pH y el tenor de P en el suelo, así como el P acumulado en las plántulas. Se encontró interacción entre las dosis de P y la cachaza para todas las variables, excepto para el pH y el carbono soluble. El fosfato con la adición de cachaza aumentó la actividad microbiana y el fósforo disponible en el suelo, reflejándose en la mayor acumulación de P en las plantas.The objective of the work was to evaluate the effect of different doses of phosphate fertilizer with the addition of sugar cane industry filter cake on the soil microbial activity and soil and plant P concentration in sugar cane. The experiment was carried out in vegetation house at Jaboticabal, Brazil, in 2013, and the sugar cane seedlings variety "CTC 05"was used as tests plant. The experimental units were pots containing Hapludox. A completely randomized design was used, with factorial arrangement of 5x2 and three repetitions. The treatments were five phosphorus doses: 0, 50, 100, 200 and 400 mg dm -3 and two levels of filter cake (absence and presence). Soil respiration, acid phosphatase and dehydrogenase activity, soluble carbon, pH value, soil and plant P concentrations. There was interaction among doses of P and filter cake application for all the variables, except for the pH. The phosphate with the addition of filter cake application for all the variables, except for the pH. The phosphate with the addition of filter cake increased the microbial activity, the value of the pH and de P concentration in the soil, being reflected in a higher accumulation of P in the seedling.Fil: Saucedo Castillo, Orlando. Universidad Central "Marta Abreu" de Las Villas (Cuba)Fil: Prado, Renato de Mello. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Castellanos González, Leónides . Universidad de Cienfuegos (Cuba)Fil: Ely, Nahas. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Silva Campos, Cid Naudi. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Silva, Gilmara Pereira Da. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Assis, Luis Carlos. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil
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