Obstacles and benefits of the implementation of a reduced-rank smoother with a high resolution model of the tropical Atlantic Ocean

Most of oceanographic operational centers use three-dimensional data assimilation schemes to produce reanalyses. We investigate here the benefits of a smoother, i.e. a four-dimensional formulation of statistical assimilation. A square-root sequential smoother is implemented with a tropical Atlantic Ocean circulation model. A simple twin experiment is performed to investigate its benefits, compared to its corresponding filter. Despite model's non-linearities and the various approximations used for its implementation, the smoother leads to a better estimation of the ocean state, both on statistical (i.e. mean error level) and dynamical points of view, as expected from linear theory. Smoothed states are more in phase with the dynamics of the reference state, an aspect that is nicely illustrated with the chaotic dynamics of the North Brazil Current rings. We also show that the smoother efficiency is strongly related to the filter configuration. One of the main obstacles to implement the smoother is then to accurately estimate the error covariances of the filter. Considering this, benefits of the smoother are also investigated with a configuration close to situations that can be managed by operational center systems, where covariances matrices are fixed (optimal interpolation). We define here a simplified smoother scheme, called half-fixed basis smoother, that could be implemented with current reanalysis schemes. Its main assumption is to neglect the propagation of the error covariances matrix, what leads to strongly reduce the cost of assimilation. Results illustrate the ability of this smoother to provide a solution more consistent with the dynamics, compared to the filter. The smoother is also able to produce analyses independently of the observation frequency, so the smoothed solution appears more continuous in time, especially in case of a low frenquency observation network

Leptogenesis, Z' bosons, and the reheating temperature of the Universe

We study the impact for leptogenesis of new U(1) gauge bosons coupled to the heavy Majorana neutrinos. They can significantly enhance the efficiency of thermal scenarios in the weak washout regime as long as the Z' masses are not much larger than the reheating temperature ($M_{Z'}<10 T_{rh}$), with the highest efficiencies obtained for Z' bosons considerably heavier than the heavy neutrinos ($M_{Z'} > 100 M_1$). We show how the allowed region of the parameter space is modified in the presence of a Z' and we also obtain the minimum reheating temperature that is required for these models to be successful.Comment: 14 pages, 6 figures; One figure added, discussion on the reheating temperature extende

Immediate implants placed in fresh sockets associated to periapical infectious processes: a systematic review

Objetives: The development of treated implant surfaces, added to the increase of the aesthetic requirements by the patients has led to a change in the treatment protocols as well as the development of techniques such as the onefase implants and the immediate prosthetic loading. One of the usual contraindications of the implant treatment is the presence of periapical disease associated to the tooth to be replaced. The aim of this paper is to review the published literature on immediate implant placement in extraction sockets of teeth with periapical pathology, considering the level of scientific evidence, and following the principles of medicine and evidence-based Dentistry. Material and Methods: A search of articles published between 1982 and 2012 was conducted. The search terms immediate, dental implant, extraction, infected, periapical pathology were used. Search was limited to studies in animals and humans, published in english language. Results: 16 articles were selected from a total of 438, which were stratified according to their level of scientific evidence using the SORT criteria (Strength of Recommendation Taxonomy). Studies in both animals and humans presented high rates of implant survival, but human studies are limited to a small number of cases. Discussion and Conclusions: There is a limited evidence regarding implant placement immediately to the extraction of teeth affected by chronic periapical pathology. Following analysis of the articles, and in function of their scientific quality, a type B recommendation is given in favor of the immediate implant placement in fresh sockets associated to periapical infectious processes

Osteoquimionecrosis de los maxilares asociada a la administración de bifosfonatos por vía endovenosa: a propósito de seis casos

La osteonecrosis de los maxilares en pacientes con cáncer se asociaba, hasta ahora, con la radioterapia, aunque recientemente se han reportado numerosos casos de osteoquimionecrosis de los maxilares (OQNM) relacionada con la quimioterapia, y más concretamente con el uso de los bifosfonatos (agentes inhibidores de la actividad osteoclástica), utilizados para el tratamiento de las metástasis óseas. Los bifosfonatos inhiben la actividad osteoclástica dando lugar a una disminución de la reabsorción y la remodelación del hueso, comprometiendo su irrigación. Si bien la disminución del aporte vascular en el hueso podría presentarse en cualquier localización, parece lógico que en la mayoría de los casos afecte a los huesos maxilares debido a que su vascularización es de tipo terminal, y al hecho de que es un hueso expuesto a agresiones del medio exterior, ya sea a través del periodonto o del conducto radicular. Se presentan las complicaciones observadas en 6 casos de OQNM desencadenadas tras la ejecución de diversas terapias quirúrgicas bucales en pacientes sometidos a un tratamiento con bifosfonatos por diferentes patologías y su manejo terapéutico. El tratamiento de este tipo de OQNM suele ser insatisfactorio, ya que ninguna de las opciones terapéuticas descritas en la literatura ha obtenido buenos resultados. Todos los pacientes que van a recibir o han recibido tratamiento con bifosfonatos deben ser considerados como pacientes de riesgo de OQNM, y deben someterse a las mismas medidas profilácticas descritas para la prevención de la osteorradionecrosis

Implantes en pacientes VIH positivo. A propósito de tres casos

El aumento de la calidad y la esperanza de vida de los pacientes VIH-positivo, ha hecho que la solicitud de tratamiento estético dental se haya incrementado significativamente en estos pacientes, considerándose actualmente las prótesis implantosoportadas como una opción terapéutica válida. Se presentan 3 pacientes varones, VIH-positivo que acudieron a nuestro Servicio de Implantología Bucofacial, para valorar una posible rehabilitación implantosoportada. La evolución clínica de los pacientes había sido estable durante un periodo mínimo de 4 años. Se colocaron un total de 12 implantes (caso 1: 4 implantes Defcon®, 2 en maxilar superior y 2 en mandíbula; caso 2: 2 implantes ITI® en mandíbula; caso 3: 6 implantes Brånemark System® en maxilar superior), todos ellos bajo anestesia locorregional y siguiendo la técnica habitual. No se llevó a cabo ningún tipo de técnica de regeneración ósea guiada. No se presentaron complicaciones intra y/o postoperatorias. Tampoco se produjo ninguna alteración de los parámetros biológicos de control de la enfermedad de base tras la intervención quirúrgica. Los implantes han sido considerados como una opción de tratamiento en este tipo de pacientes pese a que su fiabilidad, no ha sido todavía establecida a largo plazo. A excepción de dos artículos (implante unitario inmediato y una rehabilitación bucal completa), ningún otro estudio ha sido publicado referente a la rehabilitación con implantes en pacientes VIH-positivo. En ambos artículos se corrobora la hipótesis que la cirugía bucal menor no aumenta el riesgo de infección locorregional en los pacientes VIH-positivo correctamente controlados, como evidenciamos en nuestros 3 casos. En el postoperatorio inmediato, no se observó ninguna disminución significativa del marcador CD4 ni de ningún otro parámetro biológico, tal como se describe en la literatura, obteniéndose una excelente curación de los tejidos blandos y duros

Effect of the local administration of betamethasone on pain, swelling and trismus after impacted lower third molar extraction. A randomized, triple blinded, controlled trial

Objectives: The aim of this study is to compare the analgesic and anti-inflammatory effects of the local postoperative administration of a single 12-mg dose of betamethasone after the surgical removal of impacted lower third molars. Study design: A split-mouth, triple-blind, randomized, placebo-controlled clinical trial of 25 patients requiring the surgical removal of symmetrical lower third molars was performed. In the experimental side, a 12-mg dose of betamethasone was administered submucosally after the surgical procedure, while in the control side a placebo (sterile saline solution) was injected in the same area. To assess postoperative pain, visual analogue scales and the consumption of rescue analgesic were used. The facial swelling and trismus were evaluated by measuring facial reference distances and maximum mouth opening. Results: There were no significant differences between the two study groups regarding postoperative pain, facial swelling and trismus. Conclusions: The injection of a single dose of betamethasone does not seem to reduce pain, facial swelling and trismus after impacted lower third molar removal when compared to placebo

Preferential tau aggregation in von Economo neurons and fork cells in frontotemporal lobar degeneration with specific MAPT variants.

Tau aggregation is a hallmark feature in a subset of patients with frontotemporal dementia (FTD). Early and selective loss of von Economo neurons (VENs) and fork cells within the frontoinsular (FI) and anterior cingulate cortices (ACC) is observed in patients with sporadic behavioral variant FTD (bvFTD) due to frontotemporal lobar degeneration (FTLD), including FTLD with tau inclusions (FTLD-tau). Recently, we further showed that these specialized neurons show preferential aggregation of TDP-43 in FTLD-TDP. Whether VENs and fork cells are prone to tau accumulation in FTLD-tau remains unclear, and no previous studies of these neurons have focused on patients with pathogenic variants in the gene encoding microtubule-associated protein tau (FTLD-tau/MAPT). Here, we examined regional profiles of tau aggregation and neurodegeneration in 40 brain regions in 8 patients with FTLD-tau/MAPT and 7 with Pick's disease (PiD), a sporadic form of FTLD-tau that often presents with bvFTD. We further qualitatively assessed the cellular patterns of frontoinsular tau aggregation in FTLD-tau/MAPT using antibodies specific for tau hyperphosphorylation, acetylation, or conformational change. ACC and mid-insula were among the regions most affected by neurodegeneration and tau aggregation in FTLD-tau/MAPT and PiD. In these two forms of FTLD-tau, severity of regional neurodegeneration and tau protein aggregation were highly correlated across regions. In FTLD-tau/MAPT, VENs and fork cells showed disproportionate tau protein aggregation in patients with V337 M, A152T, and IVS10 + 16 variants, but not in patients with the P301L variant. As seen in FTLD-TDP, our data suggest that VENs and fork cells represent preferentially vulnerable neuron types in most, but not all of the MAPT variants we studied

Cistoadenoma de glándulas salivales menores. Presentación de dos casos y revisión de la literatura

El cistoadenoma es un tumor salival benigno de origen epitelial muy infrecuente que se caracteriza por presentar múltiples proyecciones papilares y espacios microquísticos recubiertos de células cilíndricas o cuboideas. La OMS define el cistoadenoma como una neoplasia salival muy similar al tumor de Warthin, que carece de componente linfoide. La mayoría de cistoadenomas se han descrito a nivel de la laringe, la nasofaringe, así como en la glándula parótida y las glándulas lacrimales. Sin embargo, pueden localizarse con menor frecuencia en las mucosas labial y bucal, en la fosa tonsilar y en el paladar. El 35% se sitúan en las glándulas salivales menores

Salivary gland choristoma in the buccinator muscle: a case report and literature review

Salivary gland choristoma (SGCh) is defined as the presence of normal salivary tissue in an abnormal location. It is a rare entity in oral and maxillofacial region and its ethiology is unknown. The typical presentation of salivary gland heterotopia is an asymptomatic mass that may or may not produce saliva. Some examples of ectopic salivary tissue in the pituitary gland, in the lymph nodes, in the middle ear, in the neck, in the jaw, in the thyroid gland, in the mediastinum and in the rectum have been documented in literature. We report the case of a 61-year-old male presented with a bilateral tumorlike mass in the cheek. The mass was painless, of fibrous consistency and had size change with time. The histological diagnosis was salivary gland choristoma in the buccinator muscle. In this article, we will revise the characteristic of salivary gland heterotopias and we present a report case that has not been described in literature: a bilateral choristoma of salivary gland in the buccinator muscle, which should be included in the differential diagnosis of head and neck masse