POSYDON: A General-Purpose Population Synthesis Code with Detailed Binary-Evolution Simulations

Most massive stars are members of a binary or a higher-order stellar systems, where the presence of a binary companion can decisively alter their evolution via binary interactions. Interacting binaries are also important astrophysical laboratories for the study of compact objects. Binary population synthesis studies have been used extensively over the last two decades to interpret observations of compact-object binaries and to decipher the physical processes that lead to their formation. Here, we present POSYDON, a novel, binary population synthesis code that incorporates full stellar-structure and binary-evolution modeling, using the MESA code, throughout the whole evolution of the binaries. The use of POSYDON enables the self-consistent treatment of physical processes in stellar and binary evolution, including: realistic mass-transfer calculations and assessment of stability, internal angular-momentum transport and tides, stellar core sizes, mass-transfer rates and orbital periods. This paper describes the detailed methodology and implementation of POSYDON, including the assumed physics of stellar- and binary-evolution, the extensive grids of detailed single- and binary-star models, the post-processing, classification and interpolation methods we developed for use with the grids, and the treatment of evolutionary phases that are not based on pre-calculated grids. The first version of POSYDON targets binaries with massive primary stars (potential progenitors of neutron stars or black holes) at solar metallicity.Comment: 60 pages, 33 figures, 8 tables, referee's comments addressed. The code and the accompanying documentations and data products are available at https:\\posydon.or

Selective gene silencing by viral delivery of short hairpin RNA

RNA interference (RNAi) technology has not only become a powerful tool for functional genomics, but also allows rapid drug target discovery and in vitro validation of these targets in cell culture. Furthermore, RNAi represents a promising novel therapeutic option for treating human diseases, in particular cancer. Selective gene silencing by RNAi can be achieved essentially by two nucleic acid based methods: i) cytoplasmic delivery of short double-stranded (ds) interfering RNA oligonucleotides (siRNA), where the gene silencing effect is only transient in nature, and possibly not suitable for all applications; or ii) nuclear delivery of gene expression cassettes that express short hairpin RNA (shRNA), which are processed like endogenous interfering RNA and lead to stable gene down-regulation. Both processes involve the use of nucleic acid based drugs, which are highly charged and do not cross cell membranes by free diffusion. Therefore, in vivo delivery of RNAi therapeutics must use technology that enables the RNAi therapeutic to traverse biological membrane barriers in vivo. Viruses and the vectors derived from them carry out precisely this task and have become a major delivery system for shRNA. Here, we summarize and compare different currently used viral delivery systems, give examples of in vivo applications, and indicate trends for new developments, such as replicating viruses for shRNA delivery to cancer cells

Performance Analysis of Selection Combining Over Correlated Nakagami-m Fading Channels with Constant Correlation Model for Desired Signal and Cochannel Interference

A very efficient technique that reduces fading and channel interference influence is selection diversity based on the signal to interference ratio (SIR). In this pa¬per, system performances of selection combiner (SC) over correlated Nakagami-m channels with constant correlation model are analyzed. Closed-form expressions are obtained for the output SIR probability density function (PDF) and cumulative distribution function (CDF) which is main contribution of this paper. Outage probability and the average error probability for coherent, noncoherent modulation are derived. Numerical results presented in this paper point out the effects of fading severity and cor¬relation on the system performances. The main contribu¬tion of this analysis for multibranch signal combiner is that it has been done for general case of correlated co-channel interference (CCI)

MIguración y escuela: una frontera de desafíos para el enseño de Historia en la ciudad de Medianeira

Artigo apresentado como trabalho de conclusão de curso da Especialização em História e América Latina pela Universidade Federal da Integração Latino-Americana (UNILA)O artigo analisa os processos migratórios com destino em Medianeira/PR, considerando-a, na região fronteiriça, um dos circuitos imigrantes em busca de trabalho. A pesquisa mostra como cidades do oeste do Paraná, no caso específico de Medianeira, também se inserem na região de fronteira, geralmente caracterizada só pela região tríplice fronteira de Foz do Iguaçu, Puerto Iguazu e Ciudad del Leste. Os filhos dos migrantes acessam o ensino público da cidade e conformam a escola como espaços de transnacionalidade. Os objetivos da pesquisa consistem em identificar os problemas de adaptação e preconceitos sofridos; investigar a percepção dos professores da rede estadual de ensino sobre os contextos dos estudantes migrantes; analisar os impactos do contexto de migração no espaço escolar; e propor ações que a escola possa utilizar no processo de acolhimento desses estudantes. A pesquisa tem uma abordagem teórica-metodológica embasada na pesquisa coletiva com grupos focais. Para tanto, foi realizada uma oficina com estudantes imigrantes e outra com professores da rede pública estadual de Medianeira. As oficinas articulam uma síntese entre teoria e prática, e contribuem para levantamentos dos desafios frente a presença de imigrantes no espaço escolar, bem como possíveis soluções para os desafios enfrentados.El artículo analiza los procesos migratorios con destino a Medianeira/PR, tomando en cuenta, la región fronteriza, uno de los campos de inmigración en busca de trabajo. La investigación muestra cómo las ciudades del oeste de Paraná, de modo específico de Medianeira, también se invite en la región de frontera de Foz do Iguaçu, Puerto Iguazú y Ciudad del Leste. Los hijos de los migrantes acesan al enseño público de la ciudad y conforman la escuela como espacios de transnacionalidad. Los objetivos de la investigación son identificar los problemas de adaptación y preconceptos sufridos; investigar la percepción de los maestros de la red estadual de enseño sobre los contextos de los estudiantes migrantes; analizar los impactos del contexto de migración en el espacio escolar; y proponer acciones que la escuela pueda usar en el proceso de acollida de estos estudiantes. La investigación tiene un enfoque teórico- metodológico basado y la investigación colectiva con grupos focales. Con este fin, se realizó una oficina con estudiantes inmigrantes y otra con maestros de la red pública de Medianeira. Las oficinas articulan una síntesis entre teoría y práctica, y contribuyen para levantamientos de desafíos ante la presencia de inmigrantes en el espacio escolar, bien cómo las posibles de soluciones a los desafíos enfrentado