798 research outputs found

    Phylogenetic Position of the Acariform Mites: Sensitivity to Homology Assessment under Total Evidence

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    Background: Mites (Acari) have traditionally been treated as monophyletic, albeit composed of two major lineages: Acariformes and Parasitiformes. Yet recent studies based on morphology, molecular data, or combinations thereof, have increasingly drawn their monophyly into question. Furthermore, the usually basal (molecular) position of one or both mite lineages among the chelicerates is in conflict to their morphology, and to the widely accepted view that mites are close relatives of Ricinulei. Results: The phylogenetic position of the acariform mites is examined through employing SSU, partial LSU sequences, and morphology from 91 chelicerate extant terminals (forty Acariformes). In a static homology framework, molecular sequences were aligned using their secondary structure as guide, whereby regions of ambiguous alignment were discarded, and pre-aligned sequences analyzed under parsimony and different mixed models in a Bayesian inference. Parsimony and Bayesian analyses led to trees largely congruent concerning infraordinal, well-supported branches, but with low support for inter-ordinal relationships. An exception is Solifugae + Acariformes (P. P = 100%, J. = 0.91). In a dynamic homology framework, two analyses were run: a standard POY analysis and an analysis constrained by secondary structure. Both analyses led to largely congruent trees; supporting a (Palpigradi (Solifugae Acariformes)) clade and Ricinulei as sister group of Tetrapulmonata with the topology (Ricinulei (Amblypygi (Uropygi Araneae))). Combined analysis with two different morphological data matrices were run in order to evaluate the impact of constraining the analysis on the recovered topology when employing secondary structure as a guide for homology establishment. The constrained combined analysis yielded two topologies similar to the exclusively molecular analysis for both morphological matrices, except for the recovery of Pedipalpi instead of the (Uropygi Araneae) clade. The standard (direct optimization) POY analysis, however, led to the recovery of trees differing in the absence of the otherwise well-supported group Solifugae + Acariformes. Conclusions: Previous studies combining ribosomal sequences and morphology often recovered topologies similar to purely morphological analyses of Chelicerata. The apparent stability of certain clades not recovered here, like Haplocnemata and Acari, is regarded as a byproduct of the way the molecular homology was previously established using the instrumentalist approach implemented in POY. Constraining the analysis by a priori homology assessment is defended here as a way of maintaining the severity of the test when adding new data to the analysis. Although the strength of the method advocated here is keeping phylogenetic information from regions usually discarded in an exclusively static homology framework; it still has the inconvenience of being uninformative on the effect of alignment ambiguity on resampling methods of clade support estimation. Finally, putative morphological apomorphies of Solifugae + Acariformes are the reduction of the proximal cheliceral podomere, medial abutting of the leg coxae, loss of sperm nuclear membrane, and presence of differentiated germinative and secretory regions in the testis delivering their products into a common lumen

    Sistemas de Comunicacion Inalambrica MIMO - OFDM

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    En este articulo tutorial, se presenta la fundamentacion basica de la tecnica demodulation multiportadora OFDM (>Orthogonal Frequency Division Multiplexing). Y serealiza una introduction a los sistemas de transmision MIMO (Multi-Input and MultiOutput). Adicionalmente, se muestra un resumen de las estructuras espaciales de estossistemas. Finalmente se realiza una revision, de la estructura obtenida al combinar laestructura MIMO y la tecnica de modulation OFDM

    Surface rehabilitation of Portland cement concrete (PCC) pavements using single or double surface dressings with soft bitumen, conventional or modified emulsions

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    Surface dressings are a sustainable maintenance alternative for pavements with surface distresses, due to the low amount of resources involved. This paper aims to analyze the viability of using twelve different surface dressing solutions, including three binders (conventional and modified emulsions, and a soft 160/220 bitumen) and a covering with diluted emulsion, for surface treatment of Portland cement concrete (PCC) pavements. Several test methods were used to evaluate the macrotexture, skid resistance, adhesion, and resistance to wearing on a large scale prototype. In general, single surface dressings increased further the macrotexture of the concrete pavement surface. The skid resistance of single and double surface dressings was similar. The best surface dressing in the pull-off test was that with the 160/220 bitumen. The conventional and modified emulsions presented similar mechanical adhesion in the Vialit plate test. Concerning the prototype wearing test, the best result was obtained for the double surface dressing with bitumen covered with diluted emulsion. Based on this work’s results, the surface dressings are a potential surface rehabilitation alternative for concrete pavements.This work was partially financed by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020. This work is financed by national funds through FCT - Foundation for Science and Technology, under grant agreement SFRH/BD/137421/2018 attributed to the 1st author

    Anti-de Sitter curvature radius constrained by quasars in brane-world scenarios

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    This paper is intended to investigate the luminosity due to accretion of gas in supermassive black holes (SMBHs) in the center of quasars, using a brane-world scenario naturally endowed with extra dimensions, whereon theories formulated introduce corrections in the field equations at high energies. SMBHs possess the necessary highly energetic environment for the introduction of these corrections, which are shown to produce small deviations in all SMBH properties and, consequentely, corrections in the accretion theory that supports quasars radiative processes. The radiative flux observed from quasars indicates these deviations, from which the magnitude of the AdS5_5 bulk curvature radius, and consequently the extra dimension compactification radius is estimated.Comment: 11 pages, RevTeX, Eq.(2) and (3) expanded, and comments thereon update

    Ultrasound measures of Nellore cattle supplemented of yeast and probiotic in the north of Mato Grosso.

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    The search for better results on the performance and carcass traits of cattle under grazing has required efforts in the elaboration of diets that satisfy them both the producer and the consumer; therefore, the supplementation of grazing cattle is one of the main strategies for the intensification of systems. It is important to identify the effects of dietary supplementation on bovine growth through ultrasound imaging, which in addition to being an indication of the carcass composition allows estimation of the thickness of subcutaneous fat, as it helps to protect the carcass cold shortening. The objective of this study was to evaluate bovine carcass alterations, by means of ultrasound images, finished with pasture with additives supplementation. Twenty-eight noncastrated males of the Nellore breed were randomly divided into four supplementation groups (Group 1 = Urea; Group 2 = Urea + Optygen; Group 3 = Group 2 + Yeasts; and Group 4 = Group 3 + Probiotic). The experimental area used was of eight hectares, with Brachiaria brizantha cv. BRS Piatã, subdivided into four pens. The experiment lasted for 98 days, with 14 initial days of adaptation and the remainder subdivided into three sub-periods of 28 days, with the performance of ultrasonic readings at the end of each sub-period. For the measurement of the rib eye area (REA) and the subcutaneous fat thickness of loin (SFTL), images were taken between the 12th and 13th ribs, transversal to Musculus longissimus thoracis. For fat thickness of the rump (P8), the images were taken at the junction between M. gluteos medium and M biceps femoris, with the use of vegetable oil as an acoustic coupling. Data were analyzed using the Statistical Analyzes System software in a completely randomized design. The animal of Group 3 showed high (P 0.05) was observed among treatments, with general means of 5.53 mm in the end period. It can be concluded that the use of yeasts as an additive in the supplementation of cattle to pasture presented beneficial effects on carcass composition

    Evaluation of air cleaning using functionalized asphalt mixture sprayed with TiO 2 nanoparticles

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    [Excerto] Photocatalytic asphalt mixtures have gained attention as a possible alternative to mitigate the air pollution in urban areas. The asphalt surface when functionalized with nano-TiO2 can reduce nitrogen oxides (NOx), a harmful pollutant emitted by vehicles that contributes to problems such as acid rain and public health concernsCT/MCTES sponsored this research by the projects NanoAir PTDC/FISMAC/6606/2020, MicroCoolPav EXPL/EQU-EQU/1110/2021 and UIDB/04650/2020, under the R&D from ISISE (UIDB/04029/2020) and the ARISE (LA/P/0112/2020). Also, the second and third authors would like to acknowledge the FCT for funding PRT/BD/154269/2022, 2022.00763.CEECIND, respectively

    Efficacy and safety of flexible-dose oral sildenafil citrate (Viagra((R))) in the treatment of erectile dysfunction in Brazilian and Mexican men

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    A 12-week, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of flexible-dose sildenafil citrate (Viagra((R))) treatment (25, 50 or 100 mg) in Brazilian and Mexican men with erectile dysfunction (ED) of broad-spectrum etiology. Efficacy was assessed on the basis of responses to the 15-item International Index of Erectile Function (IIEF) questionnaire, completed at baseline and after 12 weeks of treatment. At end point, mean scores for all IIEF domains of sexual function (erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction) were significantly (P < 0.0001) higher in the sildenafil group (n = 109) than in the placebo group (n = 105). These findings confirm the significant increases in frequency of penetration and frequency of maintained erections reported previously. Sildenafil treatment was well tolerated. the most common adverse events were headache and flushing. in conclusion, sildenafil is a well-tolerated and effective treatment for ED of broad-spectrum etiology in Latin American men.Hosp Albert Einstein, BR-01250000 São Paulo, BrazilTorre Hosp Angeles del Pedregal, Consultorio 827, MexicoFac Ciencias Med Santa Casa, Porto Alegre, RS, BrazilHosp Clin Cuiritiba, Curitiba, Parana, BrazilUniv Estadual Campinas, Fac Ciencias Med, Campinas, SP, BrazilClin Rio Claro, Rio Claro, SP, BrazilUniv Estadual Rio de Janeiro, Fac Med, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilHosp Servidor Publ Estadual, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

    World Press Photo 2012: the discursive construction of the Arab Spring

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    O presente artigo pretende analisar a forma como o fenómeno da Primavera Árabe foi retratado nas fotografias vencedoras do concurso World Press Photo em 2012. As fotografias jornalísticas, embora se apresentem como índices do real, condicionam frequentemente a percepção dos indivíduos e influenciam as suas práticas sociais. Também as fotografias vencedoras do World Press Photo, um dos concursos mais prestigiados de fotojornalismo, em 2012 não fogem ao construtivismo discursivo que molda a representação e a percepção dos acontecimentos. A partir da análise crítica do discurso, nomeadamente dos instrumentos teóricos da semiótica barthesiana e da semiótica social de Gunther Kress e Theo van Leeuwen, procurámos interpretar as 38 fotografias vencedoras do World Press Photo 2012, a fim de reflectirmos sobre o modo como contribuíram para a compreensão da Revolta Árabe e como despertaram o nosso interesse e a nossa imaginação para o desenrolar do conflito.ABSTRACT:This article aims to analyze how the Arab Spring phenomenon was represented in the award-winning photographs of the World Press Photo contest in 2012. Although news photographs are usually seen as indexes of the real, they often limit the perception of individuals and influence their social practices. Also the winning photographs in 2012 of the World Press Photo, one of the most prestigious photojournalism contests, do not escape the discursive constructivism that shapes the representation and perception of events. Drawing from critical discourse analysis, namely from the theoretical tools of barthesian semiotics and Gunther Kress’s and Theo van Leeuwen’s social semiotics, we sought to interpret the 38 award-winning photographs of the World Press Photo contest in 2012, in order to reflect on the way they have contributed to our understanding of the Arab Revolt and aroused our interest and imagination to the unfolding of the conflict.info:eu-repo/semantics/publishedVersio

    Influence of Altitude on the indirect Analysis of α-amylase Content on Wheat Flours

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    The objective of this study was to verify the influence of altitude on the indirect analysis of α-amylase content on wheat flours. The experimental designused was completely randomized, with eight treatments and three repetitions. The treatments consisted of the analysis of the falling number from flours of four wheat classes (basic, domestic, bread and improver) on the elevations zero, 412, 540, 761, 934, 975, 1,040 and 1,095 meters. After the trial results, under the correction of the averages above 600 meters of elevation, it was verified that there was a significant difference between the results of distinct altitudes, for the four wheat classes. When a polynomial regression is applied, for the values without correction, it was obtained that aquadratic regression equation correlates the falling number values with altitude; however, the coefficient of determination was very low, highlighting the major influence of the different equipments that were used to measure the falling number instead of the different altitudes

    Structural and Luminescence Properties of Silica-Based Hybrids Containing New Silylated-Diketonato Europium(III) Complex

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    A new betadiketonate ligand displaying a trimethoxysilyl group as grafting function and a diketone moiety as complexing site (TTA-Si = 4,4,4-trifluoro-2-(3-trimethoxysilyl)propyl)-1-3-butanedione (C4H3S)COCH[(CH2)3Si(OCH3)3]COCF3) and its highly luminescent europium(III) complex [Eu(TTA-Si)3] have been synthesized and fully characterized. Luminescent silica-based hybrids have been prepared as well with this new complex grafted on the surface of dense silica nanoparticles (28 (+/-3 nm) or on mesoporous silica particles. The covalent bonding of Eu(TTA-Si)3 inside the core of uniform silica nanoparticles (40 (+/- 5 nm) was also achieved. Luminescence properties are discussed in relation to the europium chemical environment involved in each of the three hybrids. The general methodology proposed allowed high grafting ratios and overcame chelate release and tendency to agglomeration, and it could be applied to any silica matrix (in the core or at the surface, nanosized or not, dense or mesoporous) and therefore numerous applications such as luminescent markers and luminophors could be foreseen
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