Dynamical evolution of rotating dense stellar systems with embedded black holes

Evolution of self-gravitating rotating dense stellar systems (e.g. globular clusters, galactic nuclei) with embedded black holes is investigated. The interaction between the black hole and stellar component in differential rotating flattened systems is followed. The interplay between velocity diffusion due to relaxation and black hole star accretion is investigated together with cluster rotation using 2D+1 Fokker-Planck numerical methods. The models can reproduce the Bahcall-Wolf solution $f \propto E^{1/4}$ ($n \propto r^{-7/4}$) inside the zone of influence of the black hole. Gravo-gyro and gravothermal instabilities conduce the system to a faster evolution leading to shorter collapse times with respect to the non-rotating systems. Angular momentum transport and star accretion support the development of central rotation in relaxation time scales. We explore system dissolution due to mass-loss in the presence of an external tidal field (e.g. globular clusters in galaxies).Comment: 16 pages, 23 figures, 6 table

2D Fokker-Planck models of rotating clusters

Globular clusters rotate significantly, and with the increasing amount of detailed morphologicaland kinematical data obtained in recent years on galactic globular clusters many interesting features show up. We show how our theoretical evolutionary models of rotating clusters can be used to obtain fits, which at least properly model the overall rotation and its implied kinematics in full 2D detail (dispersions, rotation velocities). Our simplified equal mass axisymmetric rotatingmodel provides detailed two-dimensional kinematical and morphological data for star clusters. The degree of rotation is not dominant in energy, but also non-negligible for the phase space distribution function, shape and kinematics of clusters. Therefore the models are well applicable for galactic globular clusters. Since previously published papers on that matter by us made it difficult to do detailed comparisons with observations we provide a much more comprehensive and easy-to-use set of data here, which uses as entries dynamical age and flattening of observed cluster andthen offers a limited range of applicable models in full detail. The method, data structure and some exemplary comparison with observations are presented. Future work will improve modelling anddata base to take a central black hole, a mass spectrum and stellar evolution into account

Kinetics of the anaerobic purification of aerobically prebiotreated olive mill wastewater

Se ha efectuado un estudio cinético del proceso de depuración anaerobia de un alpechín previamente tratado vía aerobia con objeto de eliminar la mayor parte de los compuestos fenólicos responsables de su poder inhibidor. Se utilizan dos reactores anaerobios, uno con soporte Pansil y un Testigo sin relleno, para estudiar la influencia del soporte de inmovilización tanto sobre las constantes biocinéticas como sobre la eficiencia del proceso de digestión anaerobia o biometanización de este alpechín pretratado. A diferencia de lo que ocurre con el alpechín natural, se observa sólo una pequeñísima disminución de las constantes aparentes de velocidad del proceso anaerobio al aumentar la densidad de carga. Por otra parte, no se aprecian fenómenos de inhibición en el proceso de biometanización de este agua residual previamente tratada de forma aerobiaA kinetic study has been carried out on the process of anaerobic purification of an olive mill wastewater pre-treated aerobically to eliminate the greater part of the phenolic compounds responsible for inhibition. Two anaerobic digesters were used, one with Pansil support, and the other a Reference without filling. The aim was to study the influence of the immobilization support both on the biokinetic constants and on the efficiency of the anaerobic digestion process or biomethanization of this pre-treated olive mill wastewater. In contrast to what takes place with natural olive mill wastewater, only a very small decrease in the apparent rate constants of the anaerobic process was observed on increasing load density. At the same time, no inhibition was found in the biomethanization of this aerobically pre-treated wastewate

Biodegradation of phenolic compounds present in oil-mill wastewater

Las aguas residuales de la obtención del aceite de oliva o alpechines son responsables de la mayor contaminación medioambiental de Andalucía por su elevada carga de materia orgánica. Su depuración por biometanización es difícil debido a la actividad antimicrobiana de los compuestos fenólícos. Este tipo de sustancias puede eliminarse en gran parte tratando previamente el alpechín por vía aerobia con microorganismos específicos, después de lo cual la depuración anaerobia tiene lugar sin inhibiciones, siendo la constante de velocidad cinco veces superior a la de antes del pretratamiento. En este trabajo se hace un estudio cualitativo de los fenoles por cromatografía en capa fina y cuantitativo de los fenoles totales, orto- y meta-difenoles, así como de la Demanda Química de Oxígeno del alpechín antes del tratamiento, después del pretratamiento y después de la biometanización. Se ha comprobado también la ausencia de leucoantocianinas que pudieran dar origen a fenoles polimerizadosOil-mill wastewater is the main responsible of the pollution in Andalusian due to high content of organic substances. Its depuration by methanization is difficult because of the antimicrobial activity of phenolic derivatives. These compounds can be drastically reduced by a previous aerobic treatment of the oilmill wastewater with specific microorganisms. After this pretreatment, anaerobic depuration takes place without inhibition, the velocity of the reaction being 5 times higher than before the pretreatment. In this paper a qualitative study of the phenols present in oil-mill wastewater by thin layer chromatography has been done. Beside that, quantitative determination of total phenols, ortoand meta-diphenols as well as Chemical Oxigen Demand (COD) before the treatment, after the pretreatment and after biomethanization have been carried out. Finally, leucoanthocyanins that could originate polymerized phenols have not been foun

Epidemiological and transmissibility analysis of influenza A(H1N1)v in a southern hemisphere setting: Peru

We present a preliminary analysis of 1,771 confirmed cases of influenza A(H1N1)v reported in Peru by 17 July including the frequency of the clinical characteristics, the spatial and age distribution of the cases and the estimate of the transmission potential. Age-specific frequency of cases was highest among school age children and young adults, with the lowest frequency of cases among seniors, a pattern that is consistent with reports from other countries. Estimates of the reproduction number lie in the range of 1.2 to 1.7, which is broadly consistent with previous estimates for this pandemic in other regions. Validation of these estimates will be possible as additional data become available

Utilización y tratamiento del alpechín: situación actual y perspectivas en España

The characteristics of olive mill wastewater are set out the viewpoint of their pollutant capacity and the problems arising from their tipping in olive-growing areas. The national administration's solutions for preventing pollutions of surface waters are also stated. Special detail is given to the action taken within a research and development program financed by the Spanish Government and the EEC through the Commission MEDSPA 89 for the technical-economic evaluation of different systems for eliminating and treating olive mill wastewater, in order to determine the feasibility of their introduction at industrial level. At the same time the systems currently under evaluation are described: - Intensification of natural evaporation from olive mill wastewater stored in ponds (two systems). - Physical processes using forced evaporation to eliminate the olive mill wastewater, followed by aerobic biological processes or systems of ultrafiltration and inverse osmosis for final treatment of the condensate (two systems). - Application of physico-chemical processes to eliminate the greater part of the organic components of the olive mill wastewaters and the use of aerobic biological processes or systems of ultrafiltration and inverse osmosis for final treatment of the clarified fraction (three systems). - Biological process for the complete treatment of the olive mill wastewaters by the successive application of processes: bioconversion, biomethanisation, aerobic treatment, and physico-chemical treatment. Treatment yields of the order of 99,6% are achieved, at the same time obtaining by-products of commercial interest (one system).Las características de los alpechines se establecen desde el punto de vista de su capacidad contaminante y de los problemas típicos que surgen en las zonas de cultivo del olivo. También están descritas las soluciones de la administración del Estado para la prevención de la contaminación de aguas de superficie. Se detallan especialmente los puntos de acción incluidos dentro de un programa de Investigación y Desarrollo financiado por el Gobierno Español y la CEE a través de la comisión MEDSPA 89, para la evaluación técnica y económica de diferentes sistemas de eliminación y tratamiento de alpechines, con el fin de determinar la conveniencia de su introducción a nivel industrial. Al mismo tiempo se describen los sistemas actuales sometidos a evaluación: - Intensificación de la evaporación natural de alpechines almacenados en balsas. - Procesos físicos de evaporación forzada para eliminar este agua residual, seguido de procesos biológicos aerobios o sistemas de ultrafiltración y osmosis inversa para el tratamiento final de los condensados (dos sistemas). - Aplicación de procesos físico-químicos para eliminar la mayor parte de la materia orgánica del alpechín, y uso de procesos biológicos aerobios o sistemas de ultrafiltración y osmosis inversa para el tratamiento final de la fracción clarificada (tres sistemas). - Proceso biológico para la depuración integral del alpechín mediante la aplicación sucesiva de los procesos: bioconversión, biometanización, tratamiento aerobio, y tratamiento físico-químico. Se consiguieron rendimientos del orden del 99,6%, con la obtención simultánea de subproductos de interés comercial (un sistema)

N-body Models of Rotating Globular Clusters

We have studied the dynamical evolution of rotating globular clusters with direct $N$-body models. Our initial models are rotating King models; we obtained results for both equal-mass systems and systems composed out of two mass components. Previous investigations using a Fokker-Planck solver have revealed that rotation has a noticeable influence on stellar systems like globular clusters, which evolve by two-body relaxation. In particular, it accelerates their dynamical evolution through the gravogyro instability. We have validated the occurence of the gravogyro instability with direct $N$-body models. In the case of systems composed out of two mass components, mass segregation takes place, which competes with the rotation in the acceleration of the core collapse. The "accelerating" effect of rotation has not been detected in our isolated two-mass $N$-body models. Last, but not least, we have looked at rotating $N$-body models in a tidal field within the tidal approximation. It turns out that rotation increases the escape rate significantly. A difference between retrograde and prograde rotating star clusters occurs with respect to the orbit of the star cluster around the Galaxy, which is due to the presence of a ``third integral'' and chaotic scattering, respectively.Comment: 16 pages, 17 figures, accepted by MNRA

Influencia de la concentración de sustrato sobre la cinética del proceso de biometanización del alpechín, en biorreactores de lecho fluidizado con microorganismos inmovilizados

A kinetic study has been made of the anaerobic olive mill wastewater fermentation process in fluid bed bioreactors containing clay supports in suspension, on which the microorganisms responsible for the process have been immobilized. Four concentrations of wastewater have been used (10%, 20%, 40% and 80%) to study the influence of the substrate concentration, and at the same time, of the immobilization support, on the biokinetic constants of the continuous process. The Chen-Hashimoto model of methane production has been applied, obtaining the values of the kinetic parameters μmax and K for each case studied. The values of these parameters decreased considerably with increasing concentration of influent wastewater, though this decrease varied depending on the support used.Se ha efectuado un estudio cinético del proceso de fermentación anaerobia del alpechín en biorreactores de lecho fluidizado que contienen en suspensión soportes de tipo arcilloso sobre los que se han inmovilizado los microorganismos responsables del proceso. Se utilizan cuatro concentraciones de alpechín (10%, 20%, 40% y 80%) para estudiar la influencia de la concentración de sustrato sobre las constantes biocinéticas del proceso en régimen continuo, estudiándose al mismo tiempo la influencia del soporte de inmovilización sobre las mismas. Para ello, se aplica el modelo de Chen-Hashimoto de producción de metano, obteniéndose los valores de los parámetros cinéticos μmax y K, para cada uno de los casos estudiados. Se obtiene una disminución considerable de los valores de estos parámetros al aumentar la concentración de alpechín utilizada como influente, si bien este descenso de las constantes cinéticas varia según el soporte considerado

Factors associated with producing a scientific publication during medical training: evidence from a cross-sectional study of 40 medical schools in Latin America [version 2; peer review: 2 approved]

"Background: Scientific publication during medical training is key to promoting enduring cutting-edge knowledge. The promotion of science among medical students in Latin America is a multisectoral issue that is hampered by the lack of governmental knowledge to invest in national research, as well as by the lack of support from local universities. This study aims to determine the factors associated with the production of a scientific publication during medical training among Latin American medical students of local scientific societies. Methods: This is a secondary data analysis of a cross-sectional study conducted in 2016 that assessed the use of information and communication technologies (ICTs) among medical students from 40 local scientific societies of medical students affiliated with FELSOCEM. Teams from each local scientific society surveyed self-reported scientific publications and explored their association with socioeconomic, academic, and research training conditions. We applied nested models to identify the covariates associated with selfreported scientific publication, obtaining a parsimonious mixedeffects multilevel model grouped by medical scientific society. Results: Of 11,587 participants, the prevalence of scientific publications increased in 36% among medical students affiliated to a Scientific Society of Medical Students [parsimonious prevalence ratio (pPR)=1.36, 95%CI=1.16–1.59], 51% among medical students with advanced English proficiency [pPR=1.51, 95%CI=1.21 – 1.87], 85% among medical students who attended a scientific writing skills course [pPR=1.85, 95%CI=1.59–2.15], 81% among medical students who use Sci-Hub [pPR=1.81, 95%CI=1.50–2.20], and 108% among medical students who have access to a pirated academic account [pPR=2.08, 95%CI=1.83–2.36]. Conclusions: Producing a scientific publication among medical students is associated with being affiliated to a scientific society of medical students, English proficiency, training in scientific writing, use of Sci-Hub, and pirated academic accounts. The results will help clinical educators and medical programs improve resources for training students in high-quality research