Cyanobacteria phylogenetic studies reveal evidence for polyphyletic genera from thermal and freshwater habitats

Cyanobacteria are among the most diverse morphological microorganisms that inhabit a great variety of habitats. Their presence in the Azores, a volcanic archipelago of nine islands in the middle of the North Atlantic Ocean, has already been reported. However, due to the high diversity of cyanobacteria habitats, their biodiversity is still understudied, mainly in extreme environments. To address this, a total of 156 cyanobacteria strains from Azores lakes, streams, thermal and terrestrial habitats were isolated. Identification was made based on a polyphasic approach using classical taxonomy (morphological characteristics and environmental data) and phylogeny among 81 strains assessed by maximum likelihood and Bayesian analysis of 16S rDNA partial sequences. The 156 isolates showed a high genera diversity (38) belonging to the orders Chroococcales, Nostocales, Oscillatoriales, and Synechococcales. Eleven new genera for the Azores habitats are here reported, reinforcing that cyanobacteria biodiversity in these islands is still much understudied. Phylogenetic analysis showed 14 clusters associated with these cyanobacteria orders, with evidence for six new genera and valuable information towards Microchaete/Coleospermum taxonomic revision that better reflects species environmental distribution. These results emphasize the need for cyanobacteria taxonomy revisions, through polyphasic studies, mainly in Synechococcales order and in the Microchaete/Coleospermum, Nostoc, and Anabaena genera.Rita Cordeiro was supported by a Ph.D. grant (M3.1.a/F/017/2015) from the Fundo Regional da Ciência e Tecnologia (FRCT). This work was funded by FEDER funds through the Interreg-MAC 2014-2020 Program under the projects REBECA - Red de excelencia en biotecnología azul (algas) de la región macaronesia (MAC1.1a/060) and REBECA-CCT - Red de Excelencia en Biotecnología Azul de la Región Macaronésica. Consolidación, Certificación y Transferencia (MAC2/1.1b/269), and by Portuguese National Funds, through FCT - Fundação para a Ciência e a Tecnologia, the European Union, QREN, FEDER, COMPETE, by funding the CIBIO/InBIO (project UID/BIA/ 50027/2013 and POCI-01-0145-FEDER-006821)

3D Spectroscopy of Blue Compact Galaxies. Diagnostic Diagrams

Here we present the analysis of 3D spectroscopic data of three Blue Compact Galaxies (Mrk324, Mrk370, and IIIZw102). Each of the more than 22500 spectra obtained for each galaxy has been fitted by a single gaussian from which we have inferred the velocity dispersion (sigma), the peak intensity (Ipeak), and the central wavelength (lambda_c). The analysis shows that the sigma vs Ipeak diagrams look remarkably similar to those obtained for giant extragalactic HII regions. They all present a supersonic narrow horizontal band that extends across all the range of intensities and that result from the massive nuclear star-forming regions of every galaxy. The sigma vs Ipeak diagrams present also several inclined bands of lower intensity and an even larger sigma, arising from the large galactic volumes that surround the main central emitting knots. Here we also show that the sigma vs lambda_c and lambda_c vs Ipeak diagrams, are powerful tools able to unveil the presence of high and low mass stellar clusters, and thus allow for the possibility of inferring the star formation activity of distant galaxies, even if these are not spatially resolved.Comment: 15 pages, 3 figures, accepted for publication in The Astronomical Journa

The Relation between the Radial Temperature Profile in the Chromosphere and the Solar Spectrum at Centimeter, Millimeter, Sub-millimeter, and Infrared Wavelengths

Solar observations from millimeter to ultraviolet wavelengths show that there is a temperature minimum between photosphere and chromosphere. Analysis based on semi-empirical models locate this point at about 500 km over the photosphere. The consistency of these models has been tested by means of millimeter to infrared observations. In the present work, we show that variations of the theoretical radial temperature profile near the temperature minimum impacts the brightness temperature at centimeter, submillimeter, and infrared wavelengths, but the millimeter wavelength emission remains unchanged. We found a region between 500 and 1000 km over the photosphere that remains hidden to observations at the frequencies under study in this work.Comment: Accepted in Solar Physic

Classical limit in terms of symbolic dynamics for the quantum baker's map

We derive a simple closed form for the matrix elements of the quantum baker's map that shows that the map is an approximate shift in a symbolic representation based on discrete phase space. We use this result to give a formal proof that the quantum baker's map approaches a classical Bernoulli shift in the limit of a small effective Plank's constant.Comment: 12 pages, LaTex, typos correcte

EXPERIMENTAL EVALUATION OF THE AERODYNAMIC PERFORMANCE OF SMALL WIND TURBINES CONFECTIONED IN 3D PROTOTYPING

This paper presents the experimental evaluation of the aerodynamic performance of two small wind turbines models with five blades in the Aerodynamic Tunnel Professor Debi Pada Sadhu. The models were confectioned on a reduced scale using 3D prototyping, the first one was designed using the blade element method, assuming the power coefficient of Betz, named Optimal Blade Betz (OBB) and the second is modified from the first one, named Optimal Blade Betz Modified (OBBM). The velocity distribution in the cross section of the tunnel was determined with the aid of a Pitot tube before the evaluation of the equipment. With the known tunnel velocity profile, the static torque of the prototypes were determined with the use of a digital torquemeter coupled to the machine axis, which recorded the readings for the speed range of 1 m/s to 9.88 m/s. Also with the torquemeter, were evaluated the influence of the angular position of the blades in the measured torque. The blades were designed allowing vary their angular position in the hub, thus changing the angle of attack, and by consequence, the torque produced. A photo tachometer was employed to measure the rotation of the model in free spin. With the experimental data, the curves of static torque and angular velocity were determined as a function of incident speed. Through experimental determination of the incident velocity profile and the velocity profile in the aerodynamic wake of each turbine, the variation of the amount of momentum of the outflow was evaluated, and so the power extracted by the rotor in free rotation. This study aims to contribute to the design of a real small wind turbine, informing the aerodynamic characteristics of the equipment that can be constructed with this layout. The experimental results demonstrate good approximation for torque and power to the results obtained by evaluation by element of the blade method. The turbine constructed with Optimal Betz Blades presented static torque 17.8% higher than constructed with the Modified Blades and extracted 22% more power from the air outflow

Métodos para avaliar as perdas de nitrogênio por volatilização da superfície do solo e por emissão de amônia pela folhagem de Brachiaria brizantha cv. Marandu.

bitstream/CPPSE/17732/1/Boletim16.pd

Linearization of Cohomology-free Vector Fields

We study the cohomological equation for a smooth vector field on a compact manifold. We show that if the vector field is cohomology free, then it can be embedded continuously in a linear flow on an Abelian group

Fertilização com uréia em superfície em pastagem irrigada e a volatilização de amônia.

A aplicação de uréia em superfície na pastagem pode ocasionar elevadas perdas de amônia por volatilização e uma das alternativas para minimizar esse efeito é a irrigação ou a precipitação logo após a adubação. O objetivo dessa pesquisa foi avaliar o efeito da aplicação de lâminas de água, após a adubação com uréia (75 kgN/ha) na superfície e a lanço em pastagem de colonião, nas perdas de N por volatilização. Foram realizados três experimentos em três épocas, verão, inverno e primavera. O delineamento experimental foi em faixas, em sistema de aspersão em linha, com cinco repetições. Os tratamentos foram quatro níveis de irrigação após a adubação com uréia, sendo três tratamentos com lâminas de água e um controle (sem irrigação). Um dos tratamentos consistia em elevar a umidade do solo à capacidade de campo e os outros dois eram lâminas de água intermediárias aos do controle e capacidade de campo, havendo variação conforme a estação do ano. No verão, a aplicação de apenas 3,2 mm de água elevou a umidade do solo para 52,4% da capacidade de água disponível e reduziu as perdas de N-NH3 para menos de 3,1 % do N aplicado, enquanto a ausência de irrigação provocou perdas de 30,5%. No inverno e na primavera a volatilização de N-NH3 foi baixa, mesmo na ausência de irrigação após a adubação. Na primavera, a irrigação com 16 mm de água elevou a umidade do solo à capacidade de campo e reduziu as perdas para 1,6 % do N aplicado, enquanto no controle as perdas foram de 5%