5,818 research outputs found
Skeletal alterations associated with the use of bonded rapid maxillary expansion appliance
Bonded maxillary expansion appliances have been suggested to control increases in the vertical dimension of the face after rapid maxillary expansion (RME). However, there is still no consensus in the literature about its real skeletal effects. The purpose of this prospective study was to evaluate, longitudinally, the vertical and sagittal cephalometric alterations after RME performed with bonded maxillary expansion appliance. The sample consisted of 26 children, with a mean age of 8.7 years (range: 6.9-10.9 years), with posterior skeletal crossbite and indication for RME. After maxillary expansion, the bonded appliance was used as a fixed retention for 3.4 months, being replaced by a removable retention subsequently. The cephalometric study was performed onto lateral radiographs, taken before treatment was started, and again 6.3 months after removing the bonded appliance. Intra-group comparison was made using paired t test. The results showed that there were no significant sagittal skeletal changes at the end of treatment. There was a small vertical skeletal increase in five of the eleven evaluated cephalometric measures. The maxilla displaced downward, but it did not modify the facial growth patterns or the direction of the mandible growth. Under the specific conditions of this research, it may be concluded that RME with acrylic bonded maxillary expansion appliance did promote signifciant vertical or sagittal cephalometric alterations. The vertical changes found with the use of the bonded appliance were small and probably transitory, similar to those occurred with the use of banded expansion appliances.Os aparelhos disjuntores com cobertura oclusal de acrÃlico têm sido sugeridos para controlar o aumento da dimensão vertical da face após a expansão rápida da maxila (ERM). Entretanto, ainda não há consenso na literatura sobre seu real efeito esquelético. O objetivo desse estudo prospectivo foi avaliar longitudinalmente as alterações esqueléticas verticais e sagitais após a ERM realizada com o aparelho disjuntor com cobertura oclusal. A amostra consistiu de 26 crianças, com idade média de 8,7 anos (variação: 6.9-10,9 anos), apresentando mordida cruzada posterior esquelética e indicação para ERM. Após a expansão maxilar, o aparelho foi utilizado como contenção fixa por 3,4 meses, sendo posteriormente substituÃdo por uma contenção removÃvel. O estudo cefalométrico foi realizado em telerradiografias laterais tomadas antes do inÃcio do tratamento e novamente 6,3 meses após a remoção do disjuntor. A comparação intragrupo foi feita utilizando-se o teste t pareado. Os resultados mostraram que não houve alterações esqueléticas sagitais significantes ao fim do tratamento. Houve um pequeno aumento em cinco das onze medidas cefalométricas verticais analisadas. A maxila se moveu inferiormente, porém não modificou o padrão de crescimento facial, a inclinação ou direção de crescimento mandibular. Considerando-se as condições especÃficas deste trabalho, pode-se concluir que a ERM realizada com o aparelho disjuntor com cobertura oclusal de acrÃlico não promoveu alterações esqueléticas verticais ou sagitais prejudiciais. As alterações verticais encontradas com o uso do aparelho colado foram pequenas e provavelmente transitórias, similar ao que ocorre com o uso dos aparelhos expansores bandados
The trace fractional Laplacian and the mid-range fractional Laplacian
In this paper we introduce two new fractional versions of the Laplacian. The
first one is based on the classical formula that writes the usual Laplacian as
the sum of the eigenvalues of the Hessian. The second one comes from looking at
the classical fractional Laplacian as the mean value (in the sphere) of the
1-dimensional fractional Laplacians in lines with directions in the sphere. To
obtain this second new fractional operator we just replace the mean value by
the mid-range of 1-dimensional fractional Laplacians with directions in the
sphere. For these two new fractional operators we prove a comparison principle
for viscosity sub and supersolutions and then we obtain existence and
uniqueness for the Dirichlet problem. We also show that solutions are
smooth up to the boundary when the exterior datum is also H\"older
continuous. Finally, we prove that for the first operator we recover the
classical Laplacian in the limit as
The XDSPRES CL-based package for reducing OSIRIS cross-dispersed spectra
We present a description of the CL-based package XDSPRES, which aims at being
a complete reducing facility for cross-dispersed spectra taken with the Ohio
State Infrared Imager/Spectrometer, as installed at the SOAR telescope. This
instrument provides spectra in the range between 1.2um and 2.35um in a single
exposure, with resolving power of R ~ 1200. XDSPRES consists of two tasks,
namely xdflat and doosiris. The former is a completely automated code for
preparing normalized flat field images from raw flat field exposures. Doosiris
was designed to be a complete reduction pipeline, requiring a minimum of user
interaction. General steps towards a fully reduced spectrum are explained, as
well as the approach adopted by our code. The software is available to the
community through the web site http://www.if.ufrgs.br/~ruschel/software.Comment: 14 pages, 10 figure
Management of constipation in Parkinson's disease
INTRODUCTION: Constipation is a frequent non-motor feature of Parkinson’s disease (PD). It is the most common gastrointestinal symptom of the disease and it can precede motor symptoms by as much as 20 years. Constipation can produce discomfort and affect activities of daily living, productivity and quality of life, thus warranting early diagnosis and treatment. AREAS COVERED: In this review, the safety and efficacy of traditional and novel strategies for constipation management will be discussed. A treatment algorithm for constipation in PD will be presented. EXPERT OPINION: Polyethylene glycol and lubiprostone are first-line compounds recommended by evidence-based medicine guidelines for the treatment of constipation due to slow colonic transit in PD. Management of constipation secondary to defecatory dysfunction due to pelvic floor dyssynergia can be done by levodopa or apomorphine injections, botulinum toxin type A injection into the puborectalis muscle, and nonpharmacological interventions, like biofeedback therapy or functional magnetic stimulation, which showed some benefit in PD patients with constipation, but in general more extensive studies are warranted.Fil: Rossi, Malco Damián. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Merello, Marcelo Jorge. Fundación para la Lucha Contra las Enfermedades Neurológicas de la Infancia. Instituto de Investigaciones Neurológicas "Raúl Carrea"; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Pérez Lloret, Santiago. Pontificia Universidad Católica Argentina "Santa MarÃa de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentin
La guerra como problema de la FilosofÃa
La guerra hunde profundamente sus raÃces en la filosofÃa misma. Es en el propio nivel filosófico donde de modo tácito o expreso, halla la guerra su abrigo conceptual último. Siempre bajo supuestos o argumentos especiales o graves. Las grandes corrientes de pensamiento que han logrado cobrar realidad histórica, esto es, plasmarse efectivamente en órdenes sociales concretos, en todos los casos, han admitido (o sobreentendido) a la guerra como uno de los pilares fundamentales de su plan arquitectónico. En la actualidad, las vertientes filosóficas que informan a los sistemas polÃticos militares dominantes no constituyen ninguna excepción. Luego, sino se clarifican las aguas en las fuentes filosóficas, persistirá la turbulencias en las vertientes polÃticas y continuara verificándose la guerra. Es mas, los productos altamente sofisticados de la razón proseguirán estando en servicios bélicos; particularmente aquellos alumbrados por la razón tecnológica, que tanto fascina a nuestro siglo. He ahà la tesis.Fil: Rossi, Jorge Raúl. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras
Una aproximación conceptual de las empresas de base tecnológica
Resulta indiscutible el rol del conocimiento y la innovación para el desarrollo de las
empresas y naciones. Uno de los indicadores de innovación es la transferencia de
conocimiento desde las Universidades o Centros de Investigación que puede manifestarse
en la creación de empresas de base tecnológica.
Numerosas investigaciones que toman como objeto de estudio a este tipo de empresas
avalan su contribución al desarrollo económico de la sociedad. No obstante ello, aún no
hay consenso acerca de una definición clara y generalizable; lo que trae aparejado la
dificultad de realizar comparaciones históricas y geográficas.
El siguiente trabajo se propone una revisión bibliográfica en términos históricos como
actuales sobre el concepto de Empresa de Base Tecnológica, con el fin de realizar un
análisis comparativo que refleje la evolución de este término a lo largo de los años asÃ
como también la concepción actual adoptada por los principales organismos de ciencia y
técnica del Mercosur.
Para ello se realizó un análisis exploratorio y comparativo de la bibliografÃa existente en la
temática asà como también las definiciones adoptadas por los referentes señalados.
De esta manera, el trabajo pretende lograr una aproximación conceptual que sea el
resultado del análisis de las diversas posturas planteadas y que se enmarque dentro de la
realidad de los paÃses de la región.publishedVersio
Large solutions to an anisotropic quasilinear elliptic problem
In this paper we consider existence, asymptotic behavior near the boundary and uniqueness of positive solutions to the problem: divx(|∇xu| p−2∇xu)(x, y) + divy(|∇yu| q−2∇yu)(x, y) = u r (x, y) in a bounded domain Ω⊂RN×RMΩ⊂RN×RM together with the boundary condition u (x, y) = ∞ on ∂Ω. We prove that the necessary and sufficient condition for the existence of a solution u∈W1,p,qloc(Ω)u∈Wloc1,p,q(Ω) to this problem is r > max{p−1, q−1}. Assuming that r > q−1 ≥ p−1 > 0 we will show that the exponent q controls the blow-up rates near the boundary in the sense that all points of ∂Ω share the same profile, that depends on q and r but not on p, with the sole exception of the vertical points (where the exponent p plays a role).Fil: GarcÃa Melián, Jorge. Universidad de la Laguna; EspañaFil: Rossi, Julio Daniel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Sabina de Lis, José C.. Universidad de la Laguna; Españ
The competition between incoming and outgoing fluxes in an elliptic problem
In this work we consider existence and uniqueness of positive solutions to the elliptic equation −∆u = λu in Ω, with the nonlinear boundary conditions ∂u
∂ν = u p on Γ1, ∂u ∂ν = −u q on Γ2, where Ω is a smooth bounded domain, ∂Ω = Γ1 ∪ Γ2, Γ1 ∩ Γ2 = ∅, ν is the outward unit normal, p, q > 0 and λ is a real parameter. We obtain a complete picture of the bifurcation diagram of the problem, depending on the values of p, q and the parameter λ. Our proofs are based on different techniques: variational arguments, bifurcation techniques or comparison arguments, depending on the range of parameters considered.Ministerio de Educación y CienciaFondo Europeo de Desarrollo Regiona
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