69 research outputs found
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 Mâ) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e †0.3 at 16.9 Gpcâ3 yrâ1 at the 90% confidence level
AnĂĄlise histoquĂmica foliar do amendoim: genĂłtipos 'Tatu' e SO-909 Leaf histochemical analyses of peanut: genotypes 'Tatu' and SO-909
Este trabalho teve por finalidade a anĂĄlise histoquĂmica foliar de dois genĂłtipos de amendoim (Arachis hypogaea L.), do tipo botĂąnico ValĂȘncia: SO-53 ('Tatu') e SO-909 (PI-259747), cuja literatura demonstra apresentarem respostas diferentes de resistĂȘncia Ă s principais molĂ©stias fĂșngicas foliares do Brasil. SeçÔes transversais das seguintes estruturas - pulvino, haste peciolar, raque, pulvĂnulo e folĂolo - e seçÔes paradĂ©rmicas de folĂolos coletados em dois anos agrĂcolas consecutivos, foram analisadas quanto Ă presença de alcalĂłides, amido, calose, celulose pura, celulose com pectina, cera, cristais, cutina, lignina, mucilagem, Ăłleo, resina, tanino e ureĂdeos (micrograma) por folĂolo (grama). As diferenças qualitativas histoquĂmicas observadas nos diversos tecidos, como a freqĂŒĂȘncia de tanino, alcalĂłide, pectina e Ăłleo, supostamente, podem ser responsĂĄveis pela resistĂȘncia ou suscetibilidade dos genĂłtipos Ă s molĂ©stias fĂșngicas foliares. Para fins de caracterização, mostrou-se eficiente a avaliação de pureza de celulose.<br>Leaf histochemical analyses were made in two genotypes of Arachis hypogaea L., of the Valencia group, which present different responses to some of the peanut foliar diseases. The analyses were performed on cross sections of the pulvini, petiole, rachis, pulvinulus and leaflets. The following constituents were observed: alkaloids, callose, cellulose with pectin, cristal, cutin, lignin, mucilage, oil, pure cellulose, resin, starch, tannin, wax and weight of ureides by leaflets. Some histochemical characteristics such the amount of tannin, alkaloids, pectin and oil can be produce different responses of peanut to foliar fungal diseases, and can be used in the characterization of peanut genotypes like the amount of pure cellulose and cellulose with pectin
Aspectos da organografia e anatomia foliar do amendoim: genĂłtipos so-53 e so-909 Aspects of the foliar organography and anatomy of the peanut genotypes so-53 and so-909
Estudos morfolĂłgicos foliares foram efetuados em dois genĂłtipos de amendoim (Arachis hypogaea L.), do grupo ValĂȘncia, completando informaçÔes contidas em trabalhos anteriores. O amendoim, importante cultura mundial, possui o Brasil como centro de origem e dispersĂŁo de suas espĂ©cies. Nenhuma pesquisa havia sido realizada em organografia nem em anatomia foliar, com genĂłtipos em cultivo no PaĂs. O genĂłtipo SO-53 ('Tatu') Ă© suscetĂvel Ă s mais relevantes molĂ©stias fĂșngicas foliares, ocupando a maior ĂĄrea do amendoim cultivado no Brasil. O SO-909 (PI-259747) tem sido freqĂŒentemente citado como fonte de resistĂȘncia Ă s molĂ©stias fĂșngicas foliares, em trabalhos de fitopatologia. MediçÔes macroscĂłpicas, com o uso de paquĂmetro, bem como observaçÔes microscĂłpicas, atravĂ©s de fotomicroscĂłpio, foram efetuadas. Um estudo organogrĂĄfico foi executado com as folhas de plantas de campo, bem como o estudo anatĂŽmico, com o uso de lĂąminas semipermanentes, mediante desenhos esquemĂĄticos e fotomicroscĂłpio. Os idioblastos encontrados nos folĂolos foram divididos em trĂȘs tipos, de acordo com a presença de tanino, mucilagem ou cristal. Os mucilaginosos foram separados em dois tipos, aparecendo os longos somente na superfĂcie adaxial do limbo foliolar, e os curtos, similares Ă s cĂ©lulas epidĂ©rmicas, em seção paradĂ©rmica em ambas as faces do limbo foliolar. Os pĂȘlos foram separados em trĂȘs tipos, de acordo com o tamanho: os longos, os curtos e os muito curtos. Todos tĂȘm de uma a quatro cĂ©lulas basais e uma longa apical. As cerdasÂČ, presentes nos dois genĂłtipos, foram classificadas em dois tipos, tambĂ©m conforme o tamanho: as grandes, observadas visualmente, presentes sobretudo na bainha, e as curtas, ao longo da margem foliolar, ambas multicelulares. Algumas caracterĂsticas morfolĂłgicas, como a presença e freqĂŒĂȘncia de pĂȘlos; a forma da terminação do sulco na inserção adaxial do pecĂolo-raque; a freqĂŒĂȘncia de cerdas e a espessura da lĂąmina foliolar, podem ser utilizadas na caracterização dos genĂłtipos de amendoim. A menor espessura dos folĂolos e a presença de espaços aerĂferos na epiderme da face abaxial do limbo foliolar podem ser correlacionadas Ă suscetibilidade a determinadas molĂ©stias fĂșngicas foliares do 'Tatu'.<br>Leaf morphological studies were made in two genotypes of peanut (Arachis hypogaea L.) of the Valencia group, complementing informations included in previous papers. Peanuts are an important worldwide cultivated crop which has it center of origin in Brazil. No research is known involving studies with the organography and anatomy of the Brazilian genotypes. The genotype SO-53 ('Tatu'), susceptible to all of the most important foliar diseases, occupies the major part of the cultivated peanut in Brazil. The genotype SO-909 (PI-259747) has been frequently mentioned as a source of resistant germplasm to the peanut foliar diseases in phytopathological papers. Macroscopic measurements, with the use of a pachymeter, as well as microscopic observations, by photo microscopy, were made. An organographic study was carried out with plants which were grown in field conditions, and the anatomical studies were made with the use of semi-permanent slides, through schematic drawings and photo microscopy. The idioblasts found in the leaflets were divided into three types, according to the presence of tannin, mucilage or cristal. The mucilage idioblasts could be separated into long and short types; the long appearing only on the adaxial leaflet surface, and the short, similar to epiderm cells, appearing on both surfaces. The hairs were divided into three types according to their size: long, short and very short. All types have one to four basal cells and a long apical cell. The bristles, with multicellular structure, were classified into two types: the large, visually observed, present mainly in the sheath, and the short, present along the leaflet borders. Some morphological characteristics such as hair presence and frequency, the shape of the adaxial division at the petiole rachis zone and the leaflet thickness can be used in the characteristics of peanut genotypes. To the 'Tatu', the minor thickness of leaflet and the presence of air spaces at epiderm to the abaxial surface, can be associated to the susceptibility to some foliar fungic diseases
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