1,018 research outputs found

    A Failure of Serendipity: the Square Kilometre Array will struggle to eavesdrop on Human-like ETI

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    The Square Kilometre Array (SKA) will operate in frequency ranges often used by military radar and other communications technology. It has been shown that if Extraterrestrial Intelligences (ETIs) communicate using similar technology, then the SKA should be able to detect such transmissions up to distances of ~100 pc (~300 light years) from Earth. However, Mankind has greatly improved its communications technology over the last century, dramatically reducing signal leakage and making the Earth "radio quiet". If ETIs follow the same pattern as the human race, will we be able to detect their signal leakage before they become radio quiet? We investigate this question using Monte Carlo Realisation techniques to simulate the growth and evolution of intelligent life in the Galaxy. We show that if civilisations are "human" in nature (i.e. they are only "radio loud" for ~100 years, and can only detect each other with an SKA-like instrument out to 100 pc, within a maximum communication time of 100 years), then the probability for such civilisations accidentally detecting each other is low (~10^{-7}), much lower than if other, dedicated communication techniques are permissible (e.g. optical SETI or neutrino communication).Comment: 8 pages, 2 figures, accepted for publication in the International Journal of Astrobiolog

    NextGen Big DWH: Big Data Oriented Data Warehouse Architecture for Improved Business Intelligence

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    Data Warehousing is highly essential for achieving Business Intelligence in an Enterprise. A traditional Data Warehouse is built in par with the Inmon’s Architecture which follows Extract, Transform and Load (ETL) strategy for data pre-processing and Online Analytical Processing (OLAP) for Analysis. With several recent trends like the Online Social Networks (OSNs), e-commerce and increasingnumber of internet users, the amount of data has risen exponentially. The Data is highly dynamic where existing Data Warehouse Architectures are unable to keep in par with large amount of data for processing. Though the ETL strategy performs fairly well, it consumes a lot of time for realtime data processing. To enhance the processing capability of large volumes of Data, several Big Data Technologies and frameworks are introduced. In this paper, a Big Data Oriented Data Warehouse Architecture is proposed where the Big Data Technologies are accommodated in the Data Warehouse Architecture in a highly logical manner with an essence of chronological arrangement of the Big Data technologies. A detailed Empirical Evaluation of the proposed architecture is conducted based on a survey involving big data expertsin order to validate the proposed Data Warehouse Architectureincorporating Big Data Technologies. Incorporation of Intelligent and Semantic agents is also achieved for customizing and making the Analysis of Enterprise Level data more efficientand in turn paving a way for improved Business Intelligence at the Enterprise Leve

    Chasing Flies: The use of wingbeat frequency as a communication cue in Calyptrate Flies (Diptera: Calyptratae)

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    The incidental sound produced by the oscillation of insect wings during flight provides an opportunity for species identification. Calyptrate flies include some of the fastest and most agile flying insects, capable of rapid changes in direction and the fast pursuit of conspecifics. This flight pattern makes the continuous and close recording of their wingbeat frequency difficult and limited to confined specimens. Advances in sound editor and analysis software, however, have made it possible to isolate low amplitude sounds using noise reduction and pitch detection algorithms. To explore differences in wingbeat frequency between genera and sex, 40 specimens of three-day old Sarcophaga crassipalpis, Lucilia sericata, Calliphora dubia, and Musca vetustissima were individually recorded in free flight in a temperature-controlled room. Results showed significant differences in wingbeat frequency between the four species and intersexual differences for each species. Discriminant analysis classifying the three carrion flies resulted in 77.5% classified correctly overall, with the correct classification of 82.5% of S. crassipalpis, 60% of C. dubia, and 90% of L. sericata, when both mean wingbeat frequency and sex were included. Intersexual differences were further demonstrated by male flies showing significantly higher variability than females in three of the species. These observed intergeneric and intersexual differences in wingbeat frequency start the discussion on the use of the metric as a communication signal by this taxon. The success of the methodology demonstrated differences at the genus level and encourages the recording of additional species and the use of wingbeat frequency as an identification tool for these flies

    Fibrinogen as independent risk factor for ischemic stroke

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    We have studied fibrinogen levels (Clauss technique) in atherothrombotic ischemic stroke patients, in order to determine its role as a thombogenic risk factor. Twenty nine patients (20 men and 9 women) between 25 and 79 years old were studied; they all have had a atherothrombotic stroke. They were classified into two groups according to the result of their carotid doppler ultrasonography: g1 - without carotid flow reduction (n=l 9) and g2 - with carotid flow reduction (n=10). The fibrinogen mean value was 269mg/dl in gl and 353 mg/dl in g2. There were 47% of patients in gl and 80% of patients in g2 who presented levels >300 mg/dl. The proportions of the groups were significantly different (p300 mg/dl. As diferenças obtidas entre os grupos neste estudo foram significantes. ConclusĂŁo- Considerando o nĂ­vel de risco epidemiolĂłgico de 300 mg/dl, nossos resultados sugerem que o fibrinogĂȘnio Ă© um fator de risco independente para AVC aterotrombĂłtico, especialmente naqueles com alteração de fluxo carotĂ­deo.Universidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Federal de SĂŁo Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUNIFESP, EPM, Depto. de MedicinaSciEL

    Imbalance of naive and memory T lymphocytes with sustained high cellular activation during the first year of life from uninfected children born to HIV-1-infected mothers on HAART

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    The immune consequences of in utero HIV exposure to uninfected children whose mothers were submitted to highly active antiretroviral therapy (HAART) during gestation are not well defined. We evaluated 45 HIV-exposed uninfected (ENI) neonates and 45 healthy unexposed control (CT) neonates. All HIV-infected mothers received HAART during pregnancy, and the viral load at delivery was <50 copies/mL for 56.8%. Twenty-three ENI neonates were further evaluated after 12 months and compared to 23 unexposed healthy age-matched infants. Immunophenotyping was performed by flow cytometry in cord and peripheral blood. Cord blood lymphocyte numbers did not differ between groups. However, ENI neonates had a lower percentage of naive T cells than CT neonates (CD4+, 76.6 vs 83.1%, P < 0.001; CD8+, 70.9 vs 79.6%, P = 0.003) and higher percentages of central memory T cells than CT neonates (CD4+, 13.9 vs 8.7%, P < 0.001; CD8+, 8.6 vs 4.8%, P = 0.001). CD38 mean fluorescence intensity of T cells was higher in ENI neonates (CD4+, 62.2 vs 52.1, P = 0.007; CD8+, 47.7 vs 35.3, P < 0.001). At 12 months, ENI infants still had higher mean fluorescence intensity of CD38 on T cells (CD4+, 34.2 vs 23.3, P < 0.001; CD8+, 26.8 vs 19.4, P = 0.035). Despite effective maternal virologic control at delivery, HIV-exposed uninfected children were born with lower levels of naive T cells. Immune activation was present at birth and remained until at least 12 months of age, suggesting that in utero exposure to HIV causes subtle immune abnormalities.FAPESPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Cardamonin, a schistosomicidal chalcone from Piper aduncum L. (Piperaceae) that inhibits Schistosoma mansoni ATP diphosphohydrolase

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    AbstractBackground: Schistosomiasis is one of the world's major public health problems, and praziquantel (PZQ) is the only available drug to treat this neglected disease with an urgent demand for new drugs. Recent studies indicated that extracts from Piper aduncum L. (Piperaceae) are active against adult worms of Schistosoma mansoni, the major etiological agent of human schistosomiasis.Purpose: We investigated the in vitro schistosomicidal activity of cardamonin, a chalcone isolated from the crude extract of P. aduncum. Also, this present work describes, for the first time, the S. mansoni ATP diphosphohydrolase inhibitory activity of cardamonin, as well as, its molecular docking with S. mansoni ATPDase1, in order to investigate its mode of inhibition.Methods: In vitro schistosomicidal assays and confocal laser scanning microscopy were used to evaluate the effects of cardamonin on adult schistosomes. Cell viability was measured by MTT assay, and the S. mansoni ATPase activity was determined spectrophotometrically. Identification of the cardamonin binding site and its interactions on S. mansoni ATPDase1 were made by molecular docking experiments.Results: A bioguided fractionation of the crude extract of P. aduncum was carried out, leading to identification of cardamonin as the active compound, along with pinocembrin and uvangoletin. Cardamonin (25, 50, and 100 ”M) caused 100% mortality, tegumental alterations, and reduction of oviposition and motor activity of all adult worms of S. mansoni, without affecting mammalian cells. Confocal laser scanning microscopy showed tegumental morphological alterations and changes on the numbers of tubercles of S. mansoni worms in a dose-dependent manner. Cardamonin also inhibited S. mansoni ATP diphosphohydrolase (IC50 of 23.54 ”M). Molecular docking studies revealed that cardamonin interacts with the Nucleotide-Binding of SmATPDase 1. The nature of SmATPDase 1–cardamonin interactions is mainly hydrophobic and hydrogen bonding.Conclusion: This report provides evidence for the in vitro schistosomicidal activity of cardamonin and demonstrated, for the first time, that this chalcone is highly effective in inhibiting S. mansoni ATP diphosphohydrolase, opening the route to further studies of chalcones as prototypes for new S. mansoni ATP diphosphohydrolase inhibitors

    Has the Universe always expanded ?

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    We consider a cosmological setting for which the currently expanding era is preceded by a contracting phase, that is, we assume the Universe experienced at least one bounce. We show that scalar hydrodynamic perturbations lead to a singular behavior of the Bardeen potential and/or its derivatives (i.e. the curvature) for whatever Universe model for which the last bounce epoch can be smoothly and causally joined to the radiation dominated era. Such a Universe would be filled with non-linear perturbations long before nucleosynthesis, and would thus be incompatible with observations. We therefore conclude that no observable bounce could possibly have taken place in the early universe if Einstein gravity together with hydrodynamical fluids is to describe its evolution, and hence, under these conditions, that the Universe has always expanded.Comment: 11 pages, LaTeX-ReVTeX, no figures, submitted to PR

    Fusariose do abacaxizeiro: incidĂȘncia no fruto em função da Ă©poca de produção

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    Observations on the development of "fusariose" in commercial plantations of pineapple were carried out for two years. The heaviest losses, due to Fusarium moniliforme var. subglutinans, occurred in the months of August and September, while the mildest ones, from May to July.Foram feitas avaliaçÔes periĂłdicas, por dois anos consecutivos, para quantificar a incidĂȘncia de Fusarium moniliforme var. subglutinans em frutos de abacaxi, durante os meses de produção. Foi constatado que as maiores perdas, atribuĂ­das ao patĂłgeno, ocorreram nos meses de agosto e setembro, enquanto nas colheitas de maio a julho, a incidĂȘncia do patĂłgeno foi a mais reduzida do ano agrĂ­cola

    Equation of state for Universe from similarity symmetries

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    In this paper we proposed to use the group of analysis of symmetries of the dynamical system to describe the evolution of the Universe. This methods is used in searching for the unknown equation of state. It is shown that group of symmetries enforce the form of the equation of state for noninteracting scaling multifluids. We showed that symmetries give rise the equation of state in the form p=−Λ+w1ρ(a)+w2aÎČ+0p=-\Lambda+w_{1}\rho(a)+w_{2}a^{\beta}+0 and energy density ρ=Λ+ρ01a−3(1+w)+ρ02aÎČ+ρ03a−3\rho=\Lambda+\rho_{01}a^{-3(1+w)}+\rho_{02}a^{\beta}+\rho_{03}a^{-3}, which is commonly used in cosmology. The FRW model filled with scaling fluid (called homological) is confronted with the observations of distant type Ia supernovae. We found the class of model parameters admissible by the statistical analysis of SNIa data. We showed that the model with scaling fluid fits well to supernovae data. We found that Ωm,0≃0.4\Omega_{\text{m},0} \simeq 0.4 and n≃−1n \simeq -1 (ÎČ=−3n\beta = -3n), which can correspond to (hyper) phantom fluid, and to a high density universe. However if we assume prior that Ωm,0=0.3\Omega_{\text{m},0}=0.3 then the favoured model is close to concordance Λ\LambdaCDM model. Our results predict that in the considered model with scaling fluids distant type Ia supernovae should be brighter than in Λ\LambdaCDM model, while intermediate distant SNIa should be fainter than in Λ\LambdaCDM model. We also investigate whether the model with scaling fluid is actually preferred by data over Λ\LambdaCDM model. As a result we find from the Akaike model selection criterion prefers the model with noninteracting scaling fluid.Comment: accepted for publication versio
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