From implantation to birth: insight into molecular melatonin functions

Melatonin is a lipophilic hormone synthesized and secreted mainly in the pineal gland, acting as a neuroendocrine transducer of photoperiodic information during the night. In addition to this activity, melatonin has shown an antioxidant function and a key role as regulator of physiological processes related to human reproduction. Melatonin is involved in the normal outcome of pregnancy, beginning with the oocyte quality, continuing with embryo implantation, and finishing with fetal development and parturition. Melatonin has been shown to act directly on several reproductive events, including folliculogenesis, oocyte maturation, and corpus luteum (CL) formation. The molecular mechanism of action has been investigated through several studies which provide solid evidence on the connections between maternal melatonin secretion and embryonic and fetal development. Melatonin administration, reducing oxidative stress and directly acting on its membrane receptors, melatonin thyroid hormone receptors (MT1 and MT2), displays effects on the earliest phases of pregnancy and during the whole gestational period. In addition, considering the reported positive effects on the outcomes of compromised pregnancies, melatonin supplementation should be considered as an important tool for supporting fetal development, opening new opportunities for the management of several reproductive and gestational pathologies

The sutures in dentistry

In oral surgery, the last phase of a surgical operation is represented by the tissues suture, that allows the wound lips edges approximation and their stabilization, to promote haemostasis, to avoid the alimentary residues accumulation on the incision line and allow the first intention healing. A good suture avoids that the displacing forces generated by the muscular insertions, functional movements and by the external agents destabilize or cause the surgical wound deiscence. The purpose of this study was to re-examine the suture threads characteristics, properties and biological interactions evaluating the different studies published in literature results and conclusions. In conclusion, the authors recommended the use of the different suture threads on the dependence of the oral surgery operation type that must be performed, of the patient compliance and of the various suture materials physical and biocompatibility characteristics

A new numerical strategy with space-time adaptivity and error control for multi-scale streamer discharge simulations

This paper presents a new resolution strategy for multi-scale streamer discharge simulations based on a second order time adaptive integration and space adaptive multiresolution. A classical fluid model is used to describe plasma discharges, considering drift-diffusion equations and the computation of electric field. The proposed numerical method provides a time-space accuracy control of the solution, and thus, an effective accurate resolution independent of the fastest physical time scale. An important improvement of the computational efficiency is achieved whenever the required time steps go beyond standard stability constraints associated with mesh size or source time scales for the resolution of the drift-diffusion equations, whereas the stability constraint related to the dielectric relaxation time scale is respected but with a second order precision. Numerical illustrations show that the strategy can be efficiently applied to simulate the propagation of highly nonlinear ionizing waves as streamer discharges, as well as highly multi-scale nanosecond repetitively pulsed discharges, describing consistently a broad spectrum of space and time scales as well as different physical scenarios for consecutive discharge/post-discharge phases, out of reach of standard non-adaptive methods.Comment: Support of Ecole Centrale Paris is gratefully acknowledged for several month stay of Z. Bonaventura at Laboratory EM2C as visiting Professor. Authors express special thanks to Christian Tenaud (LIMSI-CNRS) for providing the basis of the multiresolution kernel of MR CHORUS, code developed for compressible Navier-Stokes equations (D\'eclaration d'Invention DI 03760-01). Accepted for publication; Journal of Computational Physics (2011) 1-2

Modelling of dielectric barrier discharge plasma actuators for direct numerical simulations

In recent years the development of devices known as plasma actuators has advanced the promise of controlling flows in new ways that increase lift, reduce drag and improve aerodynamic efficiencies; advances that may lead to safer, more efficient and quieter aircraft. The large number of parameters (location of the actuator, orientation, size, relative placement of the embedded and exposed electrodes, materials, applied voltage, frequency) affecting the performance of plasma actuators makes their development, testing and optimisation a very complicated task. Several approaches have been proposed for developing numerical models for plasma actuators. The discharge can be modelled by physics-based kinetic methods based on first principles, by semi-empirical phenomenological approaches and by PIV-based methods where the discharge is replaced by a steady-state body force. The latter approach receives a recent interest for its easy implementation in RANS and U-RANS solvers. Here, a forcing term extracted from experiments is implemented into our high-order Navier-Stokes solver (DNS) in order to evaluate its robustness and ability to mimic the effects of a surface dielectric barrier discharge. This experimental forcing term is compared to the numerical forcing term developed by Suzen & Huang (1, 2) with an emphasis on the importance of the wall-normal component of each model

Extraction and epitopic analysis of the 53 kd envelope glycoprotein of bovine viral diarrhea virus

Epitopic analysis of the 53kd envelope glycoprotein of bovine viral diarrhea virus (BVDV) was performed. Monoclonal antibodies that neutralized virus infectivity were used in a competitive binding assay to determine the spatial orientation of epitopes. Results of the assay indicate that the panel of monoclonal antibodies defined at least two distinct antigenic domains: A, and B/C. The majority of monoclonal antibodies recognized overlapping epitopes in domain A. Antigenic domain B/C was defined by the binding of two monoclonal antibodies to gp53 from either of two viruses. The neutralizing activity of each monoclonal antibody was complement-independent. A dot-immunoblot assay, using denatured viral protein, determined the nature of each epitope. Endoglycosidase treatment indicated that the epitopes were located in or near the carbohydrate moiety of the glycoprotein;A novel method for rapid production of viral antigen was developed. Viral antigen (Singer isolate of cytopathic virus) was produced by two methods which were compared for ease of production and antigen yield. Virus was propagated in bovine turbinate (BT) cells. In one method, BVDV antigen was purified from infected BT cells by using glycerol-potassium tartrate density gradient centrifugation. In the second method, BVDV-infected BT cells were solubilized and antigen was released with the zwitterionic detergent CHAPS. Detergent was removed by chromatography and antigen was ready for immediate use, or could be stored for future use. Antigen yield by detergent solubilization was greater than gradient-purified antigen. Detergent-solubilized BVDV antigen could be detected by enzyme immunoassay at a sixteen-fold greater dilution than gradient-purified BVDV antigen. This antigen was used in an enzyme immunoassay to detect antibody to BVDV in fetal bovine sera. BVDV antigen obtained from one 150 cm[superscript]2 cell culture flask supplied sufficient antigen to assay 282 samples of fetal bovine serum. Peroxidase-labeled protein G was used to detect bovine antibody. A good correlation existed between results from enzyme immunoassay and those from viral neutralization tests

Schéma numérique asynchrone du second ordre pour la simulation des équations aux dérivées partielles linéaires

International audienceWe propose an asynchronous method for the explicit integration of multi-scale partial differential equations. This method is restricted by a local CFL (Courant Friedrichs Lewy) condition rather than the traditional global CFL condition. Moreover, contrary to other local time-stepping (LTS) methods, the asynchronous algorithm permits the selection of independent time steps in each mesh element. We derived an asynchronous Runge–Kutta 2 (ARK2) scheme from a standard explicit Runge–Kutta method and we proved that the ARK2 scheme is second order convergent. Comparing with the classical integration, the asynchronous scheme is effective in terms of computation time.Nous proposons une méthode asynchrone d'intégration explicite pour les équations aux dérivées partielles multi-échelles. Cette méthode est contrainte par une constante CFL locale au lieu de la constante CFL globale beaucoup plus restrictive. De plus et contrairement aux méthodes classiques de pas de temps local, l'algorithme asynchrone permet d'utiliser des pas de temps indépendants dans chaque élément du maillage. Nous développons un schéma asynchrone de type Runge–Kutta 2 (ARK2) à partir de la méthode Runge–Kutta explicite standard et montrons que le schéma ARK2 obtenu est convergent au second ordre. Comparativement aux méthodes classiques d'intégration synchrone, le schéma ARK2 est très efficaces en terme de temps de calcul

Avaliação da geração de biogás de um biodigestor de dejetos bovinos e suínos

Orientador : Prof. Dr. Klaus FischerCo-orientadora : Msc. Marielle FeilstreckerCo-orientador : Prof. Dr. Andreas F. GrauerDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Mestrado Profissional em Meio Ambiente Urbano e Industrial, em parceria com o Serviço Nacional de Aprendizagem Industrial e a Universität Stuttgart. Defesa: Curitiba, 11/10/2012Inclui referênciasResumo: O trabalho buscou avaliar a quantidade e qualidade do biogás gerado da biodigestão dos dejetos bovinos e suínos, de 4870 animais, os quais são criados em estábulos sob regime confinado, destinados à produção de leite e criação, respectivamente, de uma propriedade localizada no município de Carambeí, no Estado do Paraná. O biodigestor de 2500 m³, do tipo canadense, foi estudado a partir de medições, amostragens e análises laboratoriais do substrato, teores de sólidos, temperatura do biogás, pH, gás sulfídrico e composição do biogás de um sistema com operação estável e produção de biogás com alto teor de metano. O volume de biogás gerado foi medido e calculado. Avaliou-se um possível aumento na produção de biogás, assim como foi calculada a massa do agente filtrante necessária para a remoção total do gás sulfídrico produzido pelo processo. O estudo mostrou que existe um potencial para aumento da produção de biogás pela elevação da temperatura de operação do biodigestor em torno de 30 %, além de possibilidades de sua utilização para geração de energia elétrica e aquecimento do biodigestor.Abstract: This paper aimed to evaluate the amount and the quality of the biogas from the 4870 cattle and swine manure biodigester system, animals which are raised in confined spaces for milk and raising, respectively, in Carambeí, a farm based in Western Paraná State. The Canadian model biodigester with 2500 m³, was studied from samplings and laboratorial analyses of the waste, levels of solids, the biogas temperature, pH, hydrogen sulfide and biogas composition from a stable system with high level of methane biogas production. The biogas volume was measured and calculated. It was evaluated a biogas increasing production possibility as well it was calculated the filtering agent needed mass to remove the total of hydrogen sulfide produced in the process. The study showed that there is a potencial to increase the biogas production by elevating the operating temperature around 30 %, beside the possibility of its utilization for electrical energy and a heating system for the biodigester

Aa. Vv., Französische Kultur- und Medienwissenschaft. Eine Einführung

Con questo manuale di scienze della cultura e dei mezzi di comunicazione di massa francesi il team di autori offre al pubblico uno fra i migliori testi in assoluto del settore. Rivolto al vasto mondo francofono ed attento ad analizzare l’exception française all’interno del complesso tematico visto sempre nella sua globalità transnazionale, il volume propone in capitoli eccezionalmente limpidi, informati e sistematici una calibrata introduzione alle varie sfaccettature che il tema offre. Esso ..