Cosmic homogeneity: a spectroscopic and model-independent measurement

Cosmology relies on the Cosmological Principle, i.e., the hypothesis that the Universe is homogeneous and isotropic on large scales. This implies in particular that the counts of galaxies should approach a homogeneous scaling with volume at sufficiently large scales. Testing homogeneity is crucial to obtain a correct interpretation of the physical assumptions underlying the current cosmic acceleration and structure formation of the Universe. In this Letter, we use the Baryon Oscillation Spectroscopic Survey to make the first spectroscopic and model-independent measurements of the angular homogeneity scale $\theta_{\rm h}$. Applying four statistical estimators, we show that the angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent with homogeneity at large scales, and that $\theta_{\rm h}$ varies with redshift, indicating a smoother Universe in the past. These results are in agreement with the foundations of the standard cosmological paradigm.Comment: 5 pages, 2 figures, Version accepted by MNRA

On the consistency of a repulsive gravity phase in the early Universe

We exploit the possibility of existence of a repulsive gravity phase in the evolution of the Universe. A toy model with a free scalar field minimally coupled to gravity, but with the "wrong sign" for the energy and negative curvature for the spatial section, is studied in detail. The background solutions display a bouncing, non-singular Universe. The model is well-behaved with respect to tensor perturbations. But, it exhibits growing models with respect to scalar perturbations whose maximum occurs in the bouncing. Hence, large inhomogeneties are produced. At least for this case, a repulsive phase may destroy homogeneity, and in this sense it may be unstable. A newtonian analogous model is worked out; it displays qualitatively the same behaviour. The generality of this result is discussed. In particular, it is shown that the addition of an attractive radiative fluid does not change essentially the results. We discuss also a quantum version of the classical repulsive phase, through the Wheeler-de Witt equation in mini-superspace, and we show that it displays essentially the same scenario as the corresponding attractive phase.Comment: Latex file, 15 pages, 7 figures. There is a new figure, a new section and some other minor correction

Estimativa do volume de água pluvial que pode ser reutilizada na suinocultura: um estudo de caso

The West of Paran&aacute; has risen in the context of national agribusiness, where swine production is an increasing and&nbsp; highly important activity. As a result of this activity, there has been an extensive use of natural resources, resulting in environmental impacts mainly due to the high demand for water, which is used both for consumption and for cleaning the stalls. Based on this context, this study aimed to estimate the volume of rainwater that can be reused for the cleaning of installations. The study was carried out in a covered building for raising pigs measuring 1,200 m2,&nbsp; located in the district of Iguipor&atilde;, in Marechal C&acirc;ndido Rondon (Paran&aacute;, Brazil). The volume of water was estimated through data related to average precipitation, covering area of the building and sizing calculations of the volume of the cisterns needed for&nbsp; implementation in the property according to&nbsp; ABNT standards (NBR 15527).&nbsp; The results showed that the implementation of the system could represent savings of approximately 77,65% of the water used for cleaning. This demonstrates that rainwater collection decreases the impact on the use of treated water and contributes to the conservation of this important natural resource.O Oeste do Paran&aacute; tem se destacado no contexto do agroneg&oacute;cio nacional, onde a suinocultura apresenta-se como uma atividade de grande crescimento e import&acirc;ncia. Em conseq&uuml;&ecirc;ncia desta&nbsp; atividade, tem-se observado&nbsp; grande uso dos recursos naturais e impactos ao meio ambiente, principalmente devido &agrave; alta demanda por &aacute;gua, a qual &eacute; utilizada tanto para consumo, quanto para a limpeza das baias. Frente ao exposto, este trabalho teve como objetivo estimar o volume de &aacute;gua de precipita&ccedil;&atilde;o pluviom&eacute;trica que pode ser reaproveitada na limpeza das instala&ccedil;&otilde;es. O estudo foi desenvolvido em uma granja coberta de 1200 m2, localizada no distrito de Iguipor&atilde; no munic&iacute;pio de Marechal C&acirc;ndido Rondon &ndash; PR. Foi estimado o volume de &aacute;gua por meio de dados de precipita&ccedil;&atilde;o pluvial m&eacute;dia, &aacute;rea de cobertura da granja e c&aacute;lculos do dimensionamento do volume da cisterna necess&aacute;ria para a implanta&ccedil;&atilde;o na propriedade segundo NBR 15527 da ABNT. Os resultados evidenciaram que com a implanta&ccedil;&atilde;o do&nbsp; sistema seria poss&iacute;vel uma economia de aproximadamente 77,65 % da &aacute;gua consumida para limpeza. Demonstrando que a coleta de &aacute;guas pluviais&nbsp; diminui o impacto sobre o uso de &aacute;gua tratada e contribui para a preserva&ccedil;&atilde;o desse importante recurso natural

Pequenos mamíferos do Parque Estadual da Serra do Brigadeiro, Minas Gerais, Sudeste do Brasil: composição de espécies e distribuição altitudinal

The Serra do Brigadeiro State Park represents one of the few remnants of Atlantic forest in a mountainous region of the State of Minas Gerais. The terrestrial small mammal fauna of the park within a 1200- 1800m altitudinal interval was inventoried from 1996 to 2004 to generate estimates about taxonomic composition, richness, abundance, and altitudinal distribution of species. Cytogenetic analyses were carried out for selected species as an additional tool for taxonomic identifications and diversity estimates. A sampling effort of 4620 trapping-nights resulted in 21 species of rodents (families Cricetidae and Echimyidae) and marsupials (family Didelphidae) recorded, of which seven have their karyotypes described. Cumulative curves and non-parametric estimators suggest that the overall inventory is 81% complete and that at least five species are likely to be recorded with additional sampling. Species composition and diversity varied significantly across elevational belts with the lower altitudes characterized by both forest restricted and habitat-generalist species, while the upper altitudes are exclusively characterized by elevationally widespread and habitat-generalist species. Species diversity peaked at middle elevations (1300-1400m) and the putative factors responsible for this pattern are discussed.O Parque Estadual da Serra do Brigadeiro é um dos poucos remanescentes de Mata Atlântica, na Zona da Mata de Minas Gerais, localizado em região montanhosa. No período entre 1996 e 2004, foi empreendido um esforço de captura de 4620 armadilhas-noite, amostrando o intervalo altitudinal 1200-1800m, com o objetivo de inventariar a fauna de pequenos mamiferos terrestres, produzir estimativas sobre a composição taxonômica, riqueza, abundância e distribuição altitudinal das espécies desse grupo no parque. Análises citogenéticas foram realizadas em algumas espécies para auxiliar a identificação taxonômica. Foram registradas 21 espécies de roedores e marsupiais (famílias Cricetidae, Echimyidae e Didelphidae), sete das quais tiveram seus cariótipos descritos. O padrão de diversidade revelado pelas curvas cumulativas de espécie e estimadores não-paramétricos sugere que aproximadamente 81% da riqueza de espécies foi amostrada e que pelo menos cinco espécies possam ser adicionadas à listagem com esforço de captura adicional. A riqueza e composição de espécies variaram significativamente entre as cotas altimétricas, sendo as áreas mais baixas caracterizadas pela presença simultânea de espécies restritas à mata e espécies generalistas, enquanto a comunidade das áreas mais elevadas foi composta exclusivamente por espécies com ampla distribuição altitudinal e generalistas com relação ao hábitat. A maior riqueza de espécies foi detectada nas altitudes intermediárias (1300-1400m), sendo discutidos os fatores possivelmente responsáveis por esse padrão

Targeted Chromosomal Insertion of Large DNA into the Human Genome by a Fiber-Modified High-Capacity Adenovirus-Based Vector System

A prominent goal in gene therapy research concerns the development of gene transfer vehicles that can integrate exogenous DNA at specific chromosomal loci to prevent insertional oncogenesis and provide for long-term transgene expression. Adenovirus (Ad) vectors arguably represent the most efficient delivery systems of episomal DNA into eukaryotic cell nuclei. The most advanced recombinant Ads lack all adenoviral genes. This renders these so-called high-capacity (hc) Ad vectors less cytotoxic/immunogenic than those only deleted in early regions and creates space for the insertion of large/multiple transgenes. The versatility of hcAd vectors is been increased by capsid modifications to alter their tropism and by the incorporation into their genomes of sequences promoting chromosomal insertion of exogenous DNA. Adeno-associated virus (AAV) can insert its genome into a specific human locus designated AAVS1. Trans- and cis-acting elements needed for this reaction are the AAV Rep78/68 proteins and Rep78/68-binding sequences, respectively. Here, we describe the generation, characterization and testing of fiber-modified dual hcAd/AAV hybrid vectors (dHVs) containing both these elements. Due to the inhibitory effects of Rep78/68 on Ad-dependent DNA replication, we deployed a recombinase-inducible gene switch to repress Rep68 synthesis during vector rescue and propagation. Flow cytometric analyses revealed that rep68-positive dHVs can be produced similarly well as rep68-negative control vectors. Western blot experiments and immunofluorescence microscopy analyses demonstrated transfer of recombinase-dependent rep68 genes into target cells. Studies in HeLa cells and in the dystrophin-deficient myoblasts from a Duchenne muscular dystrophy (DMD) patient showed that induction of Rep68 synthesis in cells transduced with fiber-modified and rep68-positive dHVs leads to increased stable transduction levels and AAVS1-targeted integration of vector DNA. These results warrant further investigation especially considering the paucity of vector systems allowing permanent phenotypic correction of patient-own cell types with large DNA (e.g. recombinant full-length DMD genes)

SentiBench - a benchmark comparison of state-of-the-practice sentiment analysis methods

In the last few years thousands of scientific papers have investigated sentiment analysis, several startups that measure opinions on real data have emerged and a number of innovative products related to this theme have been developed. There are multiple methods for measuring sentiments, including lexical-based and supervised machine learning methods. Despite the vast interest on the theme and wide popularity of some methods, it is unclear which one is better for identifying the polarity (i.e., positive or negative) of a message. Accordingly, there is a strong need to conduct a thorough apple-to-apple comparison of sentiment analysis methods, \textit{as they are used in practice}, across multiple datasets originated from different data sources. Such a comparison is key for understanding the potential limitations, advantages, and disadvantages of popular methods. This article aims at filling this gap by presenting a benchmark comparison of twenty-four popular sentiment analysis methods (which we call the state-of-the-practice methods). Our evaluation is based on a benchmark of eighteen labeled datasets, covering messages posted on social networks, movie and product reviews, as well as opinions and comments in news articles. Our results highlight the extent to which the prediction performance of these methods varies considerably across datasets. Aiming at boosting the development of this research area, we open the methods' codes and datasets used in this article, deploying them in a benchmark system, which provides an open API for accessing and comparing sentence-level sentiment analysis methods