3,439 research outputs found
Ameloblastoma.
Tesis (Cirujano Dentista, Patología Oral)La presente revisión bibliográfica involucra el estudio de un Tumor Odontogénico poco
común, pero de gran importancia, denominado Ameloblastoma, no obstante la escasa
cantidad de casos que ocurren a nivel mundial y por lo mismo la poca información a
nivel de las actualizaciones respecto de este tema que probablemente posea el
Odontólogo General, lo que nos motiva a masificar el conocimiento adquirido por este
medio y por una futura publicación en las revistas odontológicas de circulación nacional,
colaborando de esta manera a la actualización del conocimiento de nuestros colegas y
a su vez facilitando el diagnóstico que ellos puedan tener en sus respectivos pacientes
sobre este tipo de patología.
El Ameloblastoma es un tumor localmente invasivo que la mayoría de las veces tiene
un curso benigno (1). Las metástasis son raras y se asocian a pacientes que han sido
sometidos a tratamientos quirúrgicos múltiples o extensos de sus lesiones (2). Se
conoce hace muchos años y se lo ha estudiado desde principios del siglo XIX. En su
comportamiento clínico representa un crecimiento local persistente en el área
maxilofacial con capacidad de provocar una deformidad notable antes de causar
debilitamiento grave en las estructuras que involucra (3). Se describen cuatro tipos
clínico-radiográficos: convencional, sólido, multiquístico o común (86% de todos los
casos), desmoplastico, uniquístico (13% de los casos) y periférico (extraóseo 1%
de los casos) (1 )(2), con diversos tipos histológicos que describiremos más adelante y
una contraparte maligna denominado Ameloblastoma maligno; este último de
excepcional rareza.
los Ameloblastomas son tumores de origen epitelial que pueden surgir de diversas
estructuras que se forman durante la odontogénesis, así como de entidades patológicas
de la cavidad oral, es por este motivo que se hace indispensable y necesario que
abordemos el tema desde el punto de vista global y así, comprender desde el punto de
vista anátomo-embriológico la ubicación, desarrollo y comportamiento biológico de las
posibles etiologías que lo involucrarían, (debido a que hasta el día de hoy no se conoce..
Market Power and Multimarket Contact: Some Evidence from the Spanish Hotel Industry
This is the accepted version of the following article: Fernández, N. and Marín, P. L. (1998), Market Power and Multimarket Contact: Some Evidence from the Spanish Hotel Industry. The Journal of Industrial Economics, 46(3),301–315, which has been published in final form at: http://dx.doi.org/10.1111/1467-6451.00073This paper analyses the effect of multimarket contact on firms' behaviour. According to Bernheim and Whinston [1990], firms that meet in several markets for an infinite number of periods may find it profitable to redistribute market power among markets where they are operating. We present evidence supporting this prediction by using data from the Spanish hotel industry. Moreover, we also find that the omission of variables measuring multimarket contact creates a downward bias on the effect of concentration on prices. This result questions previous conclusions about the role of competition in industries where multimarket behaviour is expected.Pedro L. Marín gratefully acknowledges financial support from Generalitat Valenciana (GV-3140/95)Publicad
Singular Lagrangian Systems on Jet Bundles
The jet bundle description of time-dependent mechanics is revisited. The
constraint algorithm for singular Lagrangians is discussed and an exhaustive
description of the constraint functions is given. By means of auxiliary
connections we give a basis of constraint functions in the Lagrangian and
Hamiltonian sides. An additional description of constraints is also given
considering at the same time compatibility, stability and second-order
condition problems. Finally, a classification of the constraints in first and
second class is obtained using a cosymplectic geometry setting. Using the
second class constraints, a Dirac bracket is introduced, extending the
well-known construction by Dirac.Comment: 65 pages. LaTeX fil
Evaluation of CNN architectures for gait recognition based on optical flow maps
This work targets people identification in video based on the way they walk (\ie gait) by using deep learning architectures. We explore the use of convolutional neural networks (CNN) for learning high-level descriptors from low-level motion features (\ie optical flow components). The low number of training samples for each subject and the use of a test set containing subjects different from the training ones makes the search of a good CNN architecture a challenging task.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Strategic Framework to Maintenance Decision Support Systems
AbstractIn current global markets the maintenance can be considered key to assurance the required function of equipments and low life cycle costs of productive equipments. In this context, the Maintenance Decision Support Systems can be relevant as strategic framework. Accordingly, in this paper, the main objective is integrating the strategic functions with Balanced Score-Card, using the Analytic Hierarchy Process, where the Key Performance Indicators are associated to goals of company. The core of this purpose is to maximize the efficiency of the plant through maintenance. The decisional problem has been modelled with four production areas, as alternatives, that were pre-selected by experts. Commercial package Expert Choice has been used to model the problem and to analyse the results. A purely strategic approach has been followed to maintenance in the industrial business; results serve as input in tactical scope
A simple methodology to estimate plant volume in nitrous oxide emission studies
Closed-chamber methodology is widely used for the estimation of greenhouse gas (GHG) emissions in agricultural systems. The volume displaced by plants inside chambers influences GHG flux estimation, although generally it is not discounted from chamber headspace in the calculation. A novel image analysis–based procedure is proposed to estimate plant volume and to assess its impact on nitrous oxide (N2O) flux estimations in a wheat (Triticum aestivum L. ‘Rimbaud’) crop. A maximum of 2.2% of the 13-L chambers was displaced by plants, leading to a systematic 0.9% overestimation in cumulative N2O emissions if plant volume was not considered. Thus, plant canopy volume should be taken into account for improving the accuracy of emissions
Utility of stabilized nitrogen fertilizers to reduce nitrate leaching under optimal management practices
Background: The inadequate application of nitrogen (N) to crops has increased the reactive N in the atmosphere and in the surface and ground waters. Stabilized N-fertilizers with nitrification (NI) and urease (UI) inhibitors have been proposed to reduce these environmental problems without affecting or even increasing crop productivity.
Aim: The objective of this study was to evaluate, in a maize–maize–wheat rotation, if the use of the NI 3, 4-dimethylpyrazole phosphate (DMPP) and the UIs N-(n-butyl) thiophosphoric triamide (NBPT) and monocarbamide dihydrogen sulfate (MCDHS) reduces N leaching without compromising yield under optimal management of N and water.
Methods: The experiment was conducted in 24 drainage lysimeters with two soil types with contrasting water holding capacity under Mediterranean irrigated conditions. The fertilizer treatments were urea, urea with DMPP, urea with NBPT, and urea with MCDHS. For the maize crop, conventional fertilizer application was split into 6- and 13-leaf stages, whereas stabilized fertilizers were applied as a single application at the 6-leaf stage. All fertilizer treatments were applied at late tillering in the wheat crop.
Results: The soil mineral N was measured at the beginning and the end of each crop season, but no differences were found among fertilizer treatments. Differences in the volume of water drained or the cumulative mass of nitrate depending on the fertilizer were not significant (three-year treatment average of 200 L m-2 and 22 kg N ha-1 in the Deep soil, and 334 L m-2 and 40 kg N ha-1 in the Shallow type, respectively). No consistent significant differences were found in agronomic parameters (chlorophyll measurements, yield, and total N uptake) between the fertilizer treatments.
Conclusion: Based on the results, the use of stabilized N-fertilizer could be recommended to reduce the number of N applications in maize without compromising grain yield but with no advantages to reduce nitrate-leaching losses if N rates are managed properly under efficient irrigation management practices
Problemas de terminología en estudios realizados acerca de "lo que el alumno sabe" sobre ciencias
In this paper we have carried out a bibliographic review of the terms currently used by science education researchers to describe «pupils' knowledge» of Science. Further, we have analised their meanings from the perspective of the methodological framework used and have offered our own proposal, as a result of that review, so as to reach a consensus on both the terminology and the possible range of meanings to bt: used. It must be pointed out that we have excluded those studies which discuss "pupils' knowledge" from a purely psychological perspective because of the enormous amount of bibliography on this topic
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