4,009 research outputs found

    Evaluation of a two-phase extraction system of carbohydrates and proteins from chlorella vulgaris utex 1803

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    Microalgae are a valuable source of high-value products and biofuels, however the high-energy cost required for the extraction of their metabolites has kept questioning on possible industrial upgrading. The aim of this study was to evaluate the effect of temperature, solvent/biomass, NaOH concentration and thermal pretreatment of the biomass in a 2-cycle carbohydrate and protein extraction system. Results shown that best conditions for carbohydrates extraction are achieved at a solvent concentration of 3.67 M, 55°C and a solvent/biomass ratio of 30mL/g. On the other side, the best conditions for protein were 3 M, 85°C and 45 mL/g. The efficiencies achieved under these conditions were 95% for carbohydrates and 98% for proteins. Using the best extraction conditions for each metabolite a thermal pre-treatment was performed at 25°C, 75°C and 105°C. Results indicate that highest efficiencies were achieved with dry biomass pretreated at 105°C, with values of 95% for carbohydrates and 98% for proteins

    Orbital debris mitigation through deorbiting with passive electrodynamic drag

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    The increase of orbital debris and the consequent proliferation of smaller objects through fragmentation are driving the need for mitigation strategies. The issue is how to deorbit the satellite with an efficient system that does not impair drastically the propellant budget of the satellite and, consequently, reduces its operating life. We have been investigating, in the framework of a European-Community-funded project, a passive system that makes use of an electrodynamics tether to deorbit a satellite through Lorentz forces. The deorbiting system will be carried by the satellite itself at launch and deployed from the satellite at the end of its life. From that moment onward the system operates passively without requiring any intervention from the satellite itself. The paper summarizes the results of the analysis carried out to show the deorbiting performance of the system starting from different orbital altitudes and inclinations for a reference satellite mass. Results can be easily scaled to other satellite masses. The results have been obtained by using a high-fidelity computer model that uses the latest environmental routines for magnetic field, ionospheric density, atmospheric density and a gravity field model. The tether dynamics is modelled by considering all the main aspects of a real system as the tether flexibility and its temperature-dependent electrical conductivity. Temperature variations are computed by including all the major external and internal input fluxes and the thermal flux emitted from the tether. The results shows that a relatively compact and light system can carry out the complete deorbit of a relatively large satellite in a time ranging from a month to less than a year starting from high LEO with the best performance occurring at low orbital inclinations

    Resistência extrema a duas estirpes do Potato virus Y (PVY) de batata transgênica, cv. Achat, expressando o gene da capa protéica do PVYO

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    The coat protein (CP) gene of the potato virus Y strain “o” (PVYO) was introduced into potato, cultivar Achat, via Agrobacterium tumefaciens-mediated transformation. Sixty three putative transgenic lines were challenged against the Brazilian strains PVY-OBR and PVY-NBR. An extremely resistant phenotype, against the two strains, was observed in one line, denominated 1P. No symptoms or positive ELISA results were observed in 16 challenged plants from this line. Another clone, named as 63P, showed a lower level of resistance. Southern blot analysis showed five copies of the CP gene in the extremely resistant line and at least three copies in the other resistant line. The stability of the integrated transgenes in the extreme resistant line was examined during several in vitro multiplications over a period of three years, with no modification in the Southern pattern was observed. The stability of the transgenes, the absence of primary infections and the relatively broad spectrum of resistance suggest that the extremely resistant line obtained in this work can be useful for agricultural purposes.O gene da capa protéica (CP) do Potato virus Y estirpe “o”, foi introduzido em batata cultivar Achat, via Agrobacterium tumefaciens. Sessenta e três linhas possivelmente transgênicas foram desafiadas com as estirpes brasileiras PVY-OBR e PVY-NBR. Uma linha apresentou extrema resistência às duas estirpes inoculadas, e foi denominado clone 1P. Não foram observados sintomas sistêmicos de infecção e as plantas foram negativas em Elisa. Outra linha, denominada clone 63P, mostrou algum nível de resistência. Análises por Southern blot indicaram a presença de pelo menos cinco cópias do gen CP no clone 1P e pelo menos três cópias no clone 63P. A estabilidade do gene introduzido no clone 1P foi avaliada durante três anos, após várias multiplicações in vitro. Não foram observadas mudanças no padrão do Southern blot. A estabilidade do transgene, na ausência de infecções primárias e relativo largo espectro de resistência sugerem que o clone 1P pode ser utilizado para fins comerciais.Fil: Romano, Eduardo. Embrapa Recursos Genéticos; BrasilFil: Ferreira, Adriana T.. Embrapa Hortaliças; BrasilFil: Dusi, André N.. Embrapa Hortaliças; BrasilFil: Proite, Karina. Embrapa Recursos Genéticos; BrasilFil: Buso, Jose A.. Embrapa Hortaliças; BrasilFil: Avila, Antonio C.. Embrapa Hortaliças; BrasilFil: Nishijima, Marta L.. Embrapa Hortaliças; BrasilFil: Nascimento, Adriana S.. Embrapa Hortaliças; BrasilFil: Bravo Almonacid, Fernando Felix. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Mentaberry, Alejandro Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Monte, Damares. Embrapa Recursos Genéticos; BrasilFil: Campos, Magnolia A.. Embrapa Recursos Genéticos; BrasilFil: Melo, Paulo Eduardo. Embrapa Hortaliças; BrasilFil: Cattony, Monica K.. No especifica;Fil: Torres, Antonio C.. Embrapa Hortaliças; Brasi

    La complejidad del conflicto ucraniano: análisis histórico y político.

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    The so-called war between Russia and Ukraine has had a significant impact on the interests of Western European countries, the United States and others involved. This conflict is not simply a dispute between two nations, but represents the interests of an imperialist world that seeks to eliminate Russia's influence in world geopolitics and maintain the leadership of the United States and the North Atlantic Organization, using Ukraine and European countries as a shield. The use of Ukraine as a battlefield is a clear strategy of the West, which has supplied armaments and military contractors to support the Ukrainian armed forces.On the other hand, Russia seeks to eliminate the development of neo-fascism in Ukraine and to defend the interests of its fellow citizens in the territories of this republic. Understanding the historical roots, causes and magnitude of the conflict is fundamental to understanding its political, economic, financial, social and diplomatic impact in today's world.La llamada guerra entre Rusia y Ucrania ha generado un impacto significativo en los intereses de los países europeos occidentales, Estados Unidos y otros involucrados. Este conflicto no es simplemente una disputa entre dos naciones, sino que representa los deseos de un mundo imperialista que busca eliminar la influencia de Rusia en la geopolítica mundial y mantener el liderazgo de Estados Unidos y la Organización del Atlántico Norte, utilizando como escudo a Ucrania y los países europeos. La decisión de Ucrania como campo de batalla es una estrategia clara de Occidente, que ha suministrado armamento y contratistas militares para apoyar a las fuerzas armadas ucranianas. Por otro lado, Rusia busca eliminar el desarrollo del neofascismo en Ucrania y defender los intereses de sus conciudadanos en los territorios de esta república. Comprender las raíces históricas, las causas y la magnitud del conflicto es fundamental para entender su impacto político, económico, financiero, social y diplomático en el mundo actual

    La complejidad del conflicto ucraniano: análisis histórico y político.

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    La llamada guerra entre Rusia y Ucrania ha generado un impacto significativo en los intereses de los países europeos occidentales, Estados Unidos y otros involucrados. Este conflicto no es simplemente una disputa entre dos naciones, sino que representa los deseos de un mundo imperialista que busca eliminar la influencia de Rusia en la geopolítica mundial y mantener el liderazgo de Estados Unidos y la Organización del Atlántico Norte, utilizando como escudo a Ucrania y los países europeos. La decisión de Ucrania como campo de batalla es una estrategia clara de Occidente, que ha suministrado armamento y contratistas militares para apoyar a las fuerzas armadas ucranianas. Por otro lado, Rusia busca eliminar el desarrollo del neofascismo en Ucrania y defender los intereses de sus conciudadanos en los territorios de esta república. Comprender las raíces históricas, las causas y la magnitud del conflicto es fundamental para entender su impacto político, económico, financiero, social y diplomático en el mundo actual

    Absolute Properties of the Eclipsing Binary Star BF Draconis

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    BF Dra is now known to be an eccentric double-lined F6+F6 binary star with relatively deep (0.7 mag) partial eclipses. Previous studies of the system are improved with 7494 differential photometric observations from the URSA WebScope and 9700 from the NFO WebScope, 106 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope and the 1 m coudé-feed spectrometer at Kitt Peak National Observatory, and 31 accurate radial velocities from the CfA. Very accurate (better than 0.6%) masses and radii are determined from analysis of the two new light curves and four radial velocity curves. Theoretical models match the absolute properties of the stars at an age of about 2.72 Gyr and [Fe/H] = −0.17, and tidal theory correctly confirms that the orbit should still be eccentric. Our observations of BF Dra constrain the convective core overshooting parameter to be larger than about 0.13 Hp. We find, however, that standard tidal theory is unable to match the observed slow rotation rates of the components\u27 surface layers

    Pulmonary arterial wall disease in COPD and interstitial lung diseases candidates for lung transplantation

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    Malaltia pulmonar obstructiva crònica; Trasplantament de pulmó; Paret arterial pulmonarEnfermedad pulmonar obstructiva crónica; Trasplante de pulmón; Pared arterial pulmonarChronic obstructive pulmonary disease; Lung transplantation; Pulmonary arterial wallBackground Pulmonary hypertension (PH) associated with lung disease has the worst prognosis of all types of PH. Pulmonary arterial vasculopathy is an early event in the natural history of chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). The present study characterized the alterations in the structure and function of the pulmonary arterial (PA) wall of COPD and ILD candidates for lung transplantation (LTx). Methods A cohort of 73 patients, 63 pre-LTx (30 COPD, 33 ILD), and ten controls underwent simultaneous right heart catheterisation and intravascular ultrasound (IVUS). Total pulmonary resistance (TPR), capacitance (Cp), and the TPR-Cp relationship were assessed. PA stiffness and the relative area of wall thickness were estimated as pulse PA pressure/IVUS pulsatility and as [(external sectional area-intimal area)/external sectional area] × 100, respectively. Results Twenty-seven percent of patients had pulmonary arterial wedge pressure > 15 mmHg and were not analyzed. PA stiffness and the area of wall thickness were increased in comparison with controls, even in patients without PH (p < 0.05). ILD patients showed a significant higher PA stiffness, and lower Cp beyond mean PA pressure (mPAP) and lower area of wall thickness than COPD patients (p < 0.05). TPR-Cp relationship was shifted downward left for ILD patients. Conclusions Significant increase of PA stiffness and area of wall thickness were present even in patients without PH and can make the diagnosis of pulmonary vasculopathy at a preclinical stage in PH-lung disease candidates for LTx. ILD patients showed the worst PA stiffness and Cp with respect to COPD.Partially support by a grant of Boston Scientific Corporation, USA

    A House a Small Company

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    The traditional models of development have allowed humanity to reach social levels never before suspected, but at the same time these developmental models have favored the social division into two large groups: one where people have many resources and manage to satisfy the most minimal cravings and others with very little or nothing, that is debated on a daily basis by hunger, unhealthiness, and lack of education. Local development starts from principles based on the resources and possibilities of communities and people grouped into families that can produce, market and self-supply the productions that are capable of developing within their environment, although under certain conditions external resources are considered. The project aims to promote favorable conditions. Therefore, that the province of Manabí can sustain its agricultural production from the families themselves, by introducing innovations in the systems or local groups of small businesses that stimulate social development in the territorial dimension, promoting a change that favors the development of zone 4 and the progress of the small business

    Detection of Sharp Symmetric Features in the Circumbinary Disk Around AK Sco

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    The Search for Planets Orbiting Two Stars (SPOTS) survey aims to study the formation and distribution of planets in binary systems by detecting and characterizing circumbinary planets and their formation environments through direct imaging. With the SPHERE Extreme Adaptive Optics instrument, a good contrast can be achieved even at small (<300 mas) separations from bright stars, which enables studies of planets and disks in a separation range that was previously inaccessible. Here, we report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco, at projected separations in the ~13--40 AU range. The sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution. We show that the observed morphology can be represented either as a highly eccentric ring around AK Sco, or as two separate spiral arms in the disk, wound in opposite directions. The relative merits of these interpretations are discussed, as well as whether these features may have been caused by one or several circumbinary planets interacting with the disk.Comment: 10 pages, 3 figures, accepted for publication in ApJ Letters. Minor (proof-level) corrections implemented in this versio

    Characterization of the distribution of water vapour for DInSAR studies on the volcanic island of Tenerife, Canary Islands

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    Measurements of ground displacement have been carried out on the entire active volcanic island of Tenerife, Canary Islands, by means of classical and advanced DInSAR techniques. The main limiting factor on the accuracy of DInSAR measurements is the distribution of the water vapour in the lower troposphere. Hence, it is yet necessary to perform a detailed spatial and temporal characterization of water vapour to understand, and to be able to carry out a direct computation of, the effect of the tropospheric delay on DInSAR results. In this sense, satellite and balloon data have been analysed to infer the variability in the distribution of water vapour and hence, the robustness of DInSAR results on the island of Tenerife.Peer reviewe
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