Navier-Stokes computation of compressible turbulent flows with a second order closure

The objective was the development of a complete second order closure for wall bounded flows, including all components of the dissipation rate tensor and a numerical solution procedure for the resulting system of equations. The main topics discussed are the closure of the pressure correlations and the viscous destruction terms in the dissipation rate equations and the numerical solution scheme based on a block-tridiagonal solver for the nine equations required for the prediction of plane or axisymmetric flows

Magnetospheric considerations for solar system ice state

The current lattice configuration of the water ice on the surfaces of the inner satellites of Jupiter and Saturn is likely shaped by many factors. But laboratory experiments have found that energetic proton irradiation can cause a transition in the structure of pure water ice from crystalline to amorphous. It is not known to what extent this process is competitive with other processes in solar system contexts. For example, surface regions that are rich in water ice may be too warm for this effect to be important, even if the energetic proton bombardment rate is very high. In this paper, we make predictions, based on particle flux levels and other considerations, about where in the magnetospheres of Jupiter and Saturn the ∼MeV proton irradiation mechanism should be most relevant. Our results support the conclusions of Hansen and McCord (2004), who related relative level of radiation on the three outer Galilean satellites to the amorphous ice content within the top 1 mm of surface. We argue here that if magnetospheric effects are considered more carefully, the correlation is even more compelling. Crystalline ice is by far the dominant ice state detected on the inner Saturnian satellites and, as we show here, the flux of bombarding energetic protons onto these bodies is much smaller than at the inner Jovian satellites. Therefore, the ice on the Saturnian satellites also corroborates the correlation

Diversidade, Biogeografia e Conservação das Begoniaceae no Estado do Espírito Santo, Brasil

A família Begoniaceae é representada no Brasil pelo gênero Begonia com aproximadamente 215 espécies encontradas principalmente na Mata Atlântica em todas as formações florestais exceto o mangue. No Espírito Santo restam aproximadamente 11% da cobertura vegetal original constituída de fragmentos de diferentes tamanhos que guardam parte da riqueza e diversidade da biota capixaba. Os objetivos deste estudo foram levantar as espécies de Begonia ocorrendo no estado do Espírito Santo, caracterizar as formações vegetais onde elas ocorrem, analisar os padrões de distribuição geográfica, diversidade e riqueza, distribuição nas Unidades de Conservação de Proteção Integral e áreas indicadas como Prioritárias para Conservação da Biodiversidade no Espírito Santo, definir o status de conservação e inferir similaridade das espécies do Espírito Santo com os outros estados brasileiros. A metodologia usada foi a comumente utilizada em levantamento florístico e taxonomia de fanerógamas, levantamento bibliográfico, consulta a herbário, observação e coleta no campo. No Espírito Santo foram encontradas 53 espécies de Begonia, sendo quatro novas para a ciência. Três táxons foram sinonimizados e um reabilitado. Dessas espécies 42 ocorrem em Floresta Ombrófila Densa, quatro em Floresta Estacional Semidecidual e quatro simultaneamente nas duas formações vegetais. Três espécies têm ocorrência nos Neotropicos, três são endêmicas da America do Sul, duas ocorrem no Brasil extra-amazônico, 45 são endêmicas da Mata Atlântica e 18 são endêmicas do Espírito Santo, sendo duas microendémicas. Segundo os critérios da IUCN, 11 espécies são consideradas Criticamente em Perigo, nove Em Perigo, cinco Vulnerável e duas Extintas na Natureza. Ainda são fornecidas, chave de identificação, descrições, distribuição, habitat, etimologia, comentários, mapas e Ilustrações

Pdf modeling for premixed turbulent combustion based on the properties of iso-concentration surfaces

In premixed turbulent flames the presence of intense mixing zones located in front of and behind the flame surface leads to a requirement to study the behavior of iso-concentration surfaces defined for all values of the progress variable (equal to unity in burnt gases and to zero in fresh mixtures). To support this study, some theoretical and mathematical tools devoted to level surfaces are first developed. Then a database of direct numerical simulations of turbulent premixed flames is generated and used to investigate the internal structure of the flame brush, and a new pdf model based on the properties of iso-surfaces is proposed

Automated computer-based detection of encounter behaviours in groups of honeybees.

Honeybees form societies in which thousands of members integrate their behaviours to act as a single functional unit. We have little knowledge on how the collaborative features are regulated by workers' activities because we lack methods that enable collection of simultaneous and continuous behavioural information for each worker bee. In this study, we introduce the Bee Behavioral Annotation System (BBAS), which enables the automated detection of bees' behaviours in small observation hives. Continuous information on position and orientation were obtained by marking worker bees with 2D barcodes in a small observation hive. We computed behavioural and social features from the tracking information to train a behaviour classifier for encounter behaviours (interaction of workers via antennation) using a machine learning-based system. The classifier correctly detected 93% of the encounter behaviours in a group of bees, whereas 13% of the falsely classified behaviours were unrelated to encounter behaviours. The possibility of building accurate classifiers for automatically annotating behaviours may allow for the examination of individual behaviours of worker bees in the social environments of small observation hives. We envisage that BBAS will be a powerful tool for detecting the effects of experimental manipulation of social attributes and sub-lethal effects of pesticides on behaviour

The Clustering of X-ray Luminous Quasars

The clustering of active galactic nuclei (AGN) sheds light on their typical large (Mpc-scale) environments, which can constrain the growth and evolution of supermassive black holes. Here we measure the clustering of luminous X-ray-selected AGN in the Stripe 82X and XMM-XXL-North surveys around the peak epoch of black hole growth, in order to investigate the dependence of luminosity on large-scale AGN environment. We compute the auto-correlation function of AGN in two luminosity bins, $10^{43}\leq L_X<10^{44.5}$ erg s$^{-1}$ at $z\sim 0.8$ and $L_X\geq 10^{44.5}$ erg s$^{-1}$ at $z\sim 1.8$, and calculate the AGN bias taking into account the redshift distribution of the sources using three different methods. Our results show that while the less luminous sample has an inferred typical halo mass that is smaller than for the more luminous AGN, the host halo mass may be less dependent on luminosity than suggested in previous work. Focusing on the luminous sample, we calculate a typical host halo mass of $\sim 10^{13}$ M$_{\odot}~h^{-1}$, which is similar to previous measurements of moderate-luminosity X-ray AGN and significantly larger than the values found for optical quasars of similar luminosities and redshifts. We suggest that the clustering differences between different AGN selection techniques are dominated by selection biases, and not due to a dependence on AGN luminosity. We discuss the limitations of inferring AGN triggering mechanisms from halo masses derived by large-scale bias.Comment: Accepted for publication in Ap

Nuevo registro de begonia inermis (Begoniaceae) para la Flora Argentina y un nuevo sinónimo de B. fischeri

Background and aims: The floristic richness of the province of Misiones (Argentina) has been increased in recent years, since new species have been cited and described for the region. The aims of this study were to revalidate and record Begonia inermis Imrsch. (Begoniaceae) for the Argentinian flora and propose a new synonym, B. hassleri C. DC., for B. fischeri Schrank. M&M: The new material collected and the new synonym were compared with the protologues and original materials of each species (except the original material of B. fischeri that could not be located), and additional specimens were also studied. The morphology was examined using optical microscopy. In addition, floras, taxonomic treatments and updated bibliography for the genus were reviewed. Results and conclusions: The description of the new record is presented, a map with its geographical distribution is added, and field photographs and a key to identify the species of Begonia L. that inhabit Misiones are provided. The number of Begonia species cited for the Argentinian Flora was not modified, since B. inermis is revalidate and also we treat B. hassleri as a synonym of B. fischeri. The ring of trichomes at the apex of the petiole of B. inermis differentiates this species from the other species of Begonia that inhabit in Argentina.Introducción y objetivos: La riqueza florística de la provincia de Misiones se ha visto incrementada en los últimos años ya que se han citado y descripto nuevas especies para la región. Los objetivos de este trabajo fueron revalidar y registrar a Begonia inermis Imrsch. (Begoniaceae) para la flora de Argentina (Misiones) y proponer un nuevo sinónimo, B. hassleri C. DC., para B. fischeri Schrank.. M&M: El nuevo material coleccionado y el nuevo sinónimo fueron comparados con los protólogos y materiales originales de cada especie (excepto el material original de B. fischeri que no pudo ser localizado), y, además, se estudiaron ejemplares adicionales. La morfología fue examinada utilizando microscopía óptica. Se revisaron floras, tratamientos taxonómicos y bibliografía actualizada para el género. Resultados y conclusiones: Se presenta la descripción del nuevo registro, se agrega un mapa con su distribución geográfica actualizada, se proveen fotografías de campo y una clave para identificar las especies de Begonia L. que ocurren en Misiones. El número de especies de Begonia citadas para la Flora Argentina no se vio modificada, ya que se restituye y se cita a B. inermis y se sinonimiza a B. hassleri bajo B. fischeri. El anillo de tricomas en el ápice del pecíolo de B. inermis, diferencia a esta especie de las otras de Begonia que habitan en la Argentina.Fil: Zanotti, Christian Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Kollmann, Ludovic J. C.. Museu de Biologia Prof. Mello Leitão; BrasilFil: Keller, Hector Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

Energetic charged particle fluxes relevant to Ganymede's polar region

The JEDI instrument made measurements of energetic charged particles near Ganymede during a close encounter with that moon. Here we find ion flux levels are similar close to Ganymede itself but outside its magnetosphere and on near wake and open field lines. But energetic electron flux levels are more than a factor of 2 lower on polar and near-wake field lines than on nearby Jovian field lines at all energies reported here. Flux levels are relevant to the weathering of the surface, particularly processes that affect the distribution of ice, since surface brightness has been linked to the open-closed field line boundary. For this reason, we estimate the sputtering rates expected in the polar regions due to energetic heavy ions. Other rates, such as those related to radiolysis by plasma and particles that can reach the surface, need to be added to complete the picture of charged particle weathering

Improving Vaccine-Induced Immunity: Can Baseline Predict Outcome?

Immune signatures measured at baseline and immediately prior to vaccination may predict the immune response to vaccination. Such pre-vaccine assessment might allow not only population-based, but also more personalized vaccination strategies ('precision vaccination'). If baseline immune signatures are predictive, the underlying mechanism they reflect may also determine vaccination outcome. Thus, baseline signatures might contribute to identifying interventional targets to be modulated prior to vaccination in order to improve vaccination responses. This concept has the potential to transform vaccination strategies and usher in a new approach to improve global health